CVE-2019-11190

The Linux kernel before 4.8 allows local users to bypass ASLR on setuid programs (such as /bin/su) because install_exec_creds() is called too late in load_elf_binary() in fs/binfmt_elf.c, and thus the ptrace_may_access() check has a race condition when reading /proc/pid/stat.

The SUSE Linux Enterprise 11 SP4 kernel version 3.0.101 was updated to receive various security and bugfixes.

The following security bugs were fixed:

• CVE-2019-11477: A sequence of SACKs may have been crafted such that one can trigger an integer overflow, leading to a kernel panic. (bsc#1137586)

• CVE-2019-11478: It was possible to send a crafted sequence of SACKs which will fragment the TCP retransmission queue. An attacker may have been able to further exploit the fragmented queue to cause an expensive linked-list walk for subsequent SACKs received for that same TCP connection.

• CVE-2019-11479: It was possible to send a crafted sequence of SACKs which will fragment the RACK send map. A remote attacker may be able to further exploit the fragmented send map to cause an expensive linked-list walk for subsequent SACKs received for that same TCP connection. This would have resulted in excess resource consumption due to low mss values.

• CVE-2014-9710: The Btrfs implementation in the Linux kernel did not ensure that the visible xattr state is consistent with a requested replacement, which allowed local users to bypass intended ACL settings and gain privileges via standard filesystem operations (1) during an xattr-replacement time window, related to a race condition, or (2) after an xattr-replacement attempt that fails because the data did not fit (bnc#923908).

• CVE-2019-5489: The mincore() implementation in mm/mincore.c in the Linux kernel allowed local attackers to observe page cache access patterns of other processes on the same system, potentially allowing sniffing of secret information. (Fixing this affects the output of the fincore program.) Limited remote exploitation may be possible, as demonstrated by latency differences in accessing public files from an Apache HTTP Server (bnc#1120843).

• CVE-2019-11190: The Linux kernel allowed local users to bypass ASLR on setuid programs (such as /bin/su) because install_exec_creds() is called too late in load_elf_binary() in fs/binfmt_elf.c, and thus the ptrace_may_access() check has a race condition when reading /proc/pid/stat (bnc#1131543).

• CVE-2018-17972: An issue was discovered in the proc_pid_stack function in fs/proc/base.c in the Linux kernel It did not ensure that only root may inspect the kernel stack of an arbitrary task, allowing a local attacker to exploit racy stack unwinding and leak kernel task stack contents (bnc#1110785).

• CVE-2019-11884: The do_hidp_sock_ioctl function in net/bluetooth/hidp/sock.c in the Linux kernel allowed a local user to obtain potentially sensitive information from kernel stack memory via a HIDPCONNADD command, because a name field may not end with a '\0' character (bnc#1134848).

• CVE-2019-11486: The Siemens R3964 line discipline driver in drivers/tty/n_r3964.c in the Linux kernel had multiple race conditions (bnc#1133188).

The following non-security bugs were fixed:

• cifs: fix uninitialized memory access (bsc#1120326).
• kabi: drop LINUX_MIB_TCPWQUEUETOOBIG snmp counter (bsc#1137586).
• kernel: Add CEX7 toleration support (bsc#1131295).
• net: ipsec: fix a kernel oops caused by reentrant workqueue (bsc#1119314).
• tcp: add tcp_min_snd_mss sysctl (bsc#1137586).
• tcp: enforce tcp_min_snd_mss in tcp_mtu_probing() (bsc#1137586).
• tcp: limit payload size of sacked skbs (bsc#1137586).
• tcp: tcp_fragment() should apply sane memory limits (bsc#1137586).
• x86/MCE: Handle 'nosmt' offlining properly (bsc#1134729).
• xfs: do not cache inodes read through bulkstat (bsc#1134102).

The SUSE Linux Enterprise 12 SP3 kernel was updated to 4.4.180 to receive various security and bugfixes.

The following security bugs were fixed:

• CVE-2019-11477: A sequence of SACKs may have been crafted such that one can trigger an integer overflow, leading to a kernel panic. (bsc#1137586)

• CVE-2019-11478: It was possible to send a crafted sequence of SACKs which will fragment the TCP retransmission queue. An attacker may have been able to further exploit the fragmented queue to cause an expensive linked-list walk for subsequent SACKs received for that same TCP connection.

• CVE-2019-11479: It was possible to send a crafted sequence of SACKs which will fragment the RACK send map. A remote attacker may be able to further exploit the fragmented send map to cause an expensive linked-list walk for subsequent SACKs received for that same TCP connection. This would have resulted in excess resource consumption due to low mss values.

• CVE-2019-3846: A flaw that allowed an attacker to corrupt memory and possibly escalate privileges was found in the mwifiex kernel module while connecting to a malicious wireless network. (bnc#1136424)

• CVE-2019-12382: An issue was discovered in drm_load_edid_firmware in drivers/gpu/drm/drm_edid_load.c in the Linux kernel There was an unchecked kstrdup of fwstr, which might allow an attacker to cause a denial of service (NULL pointer dereference and system crash). (bnc#1136586)

• CVE-2019-5489: The mincore() implementation in mm/mincore.c in the Linux kernel allowed local attackers to observe page cache access patterns of other processes on the same system, potentially allowing sniffing of secret information. (Fixing this affects the output of the fincore program.) Limited remote exploitation may be possible, as demonstrated by latency differences in accessing public files from an Apache HTTP Server. (bnc#1120843).

• CVE-2019-11833: fs/ext4/extents.c in the Linux kernel did not zero out the unused memory region in the extent tree block, which might allow local users to obtain sensitive information by reading uninitialized data in the filesystem. (bnc#1135281)

• CVE-2018-7191: In the tun subsystem in the Linux kernel before 4.13.14, dev_get_valid_name is not called before register_netdevice. This allowed local users to cause a denial of service (NULL pointer dereference and panic) via an ioctl(TUNSETIFF) call with a dev name containing a / character. This is similar to CVE-2013-4343. (bnc#1135603)

• CVE-2019-11190: The Linux kernel allowed local users to bypass ASLR on setuid programs (such as /bin/su) because install_exec_creds() is called too late in load_elf_binary() in fs/binfmt_elf.c, and thus the ptrace_may_access() check has a race condition when reading /proc/pid/stat. (bnc#1131543)

• CVE-2019-11815: An issue was discovered in rds_tcp_kill_sock in net/rds/tcp.c in the Linux kernel There was a race condition leading to a use-after-free, related to net namespace cleanup. (bnc#1134537)

• CVE-2019-11884: The do_hidp_sock_ioctl function in net/bluetooth/hidp/sock.c in the Linux kernel allowed a local user to obtain potentially sensitive information from kernel stack memory via a HIDPCONNADD command, because a name field may not end with a '\0' character. (bnc#1134848)

• CVE-2018-17972: An issue was discovered in the proc_pid_stack function in fs/proc/base.c in the Linux kernel It did not ensure that only root may inspect the kernel stack of an arbitrary task, allowing a local attacker to exploit racy stack unwinding and leak kernel task stack contents. (bnc#1110785)

• CVE-2019-11486: The Siemens R3964 line discipline driver in drivers/tty/n_r3964.c in the Linux kernel has multiple race conditions. (bnc#1133188)

The following new features were implemented:

• Updated the Chelsio cxgb4vf driver with the latest upstream patches. (fate#321660)

• Backported changes into e1000e kernel module to support…

The SUSE Linux Enterprise 12 SP3 kernel was updated to 4.4.180 to receive various security and bugfixes.

The following security bugs were fixed:

• CVE-2019-11477: A sequence of SACKs may have been crafted such that one can trigger an integer overflow, leading to a kernel panic.
• CVE-2019-11478: It was possible to send a crafted sequence of SACKs which will fragment the TCP retransmission queue. An attacker may have been able to further exploit the fragmented queue to cause an expensive linked-list walk for subsequent SACKs received for that same TCP connection.
• CVE-2019-11479: An attacker could force the Linux kernel to segment its responses into multiple TCP segments. This would drastically increased the bandwidth required to deliver the same amount of data. Further, it would consume additional resources such as CPU and NIC processing power.
• CVE-2019-3846: A flaw that allowed an attacker to corrupt memory and possibly escalate privileges was found in the mwifiex kernel module while connecting to a malicious wireless network. (bnc#1136424)
• CVE-2019-12382: An issue was discovered in drm_load_edid_firmware in drivers/gpu/drm/drm_edid_load.c in the Linux kernel, there was an unchecked kstrdup of fwstr, which might have allowed an attacker to cause a denial of service (NULL pointer dereference and system crash). (bnc#1136586)
• CVE-2019-5489: The mincore() implementation in mm/mincore.c in the Linux kernel allowed local attackers to observe page cache access patterns of other processes on the same system, potentially allowing sniffing of secret information. (Fixing this affects the output of the fincore program.) Limited remote exploitation may have been possible, as demonstrated by latency differences in accessing public files from an Apache HTTP Server. (bnc#1120843)
• CVE-2019-11833: fs/ext4/extents.c in the Linux kernel did not zero out the unused memory region in the extent tree block, which might have allowed local users to obtain sensitive information by reading uninitialized data in the filesystem. (bnc#1135281)
• CVE-2018-7191: In the tun subsystem in the Linux kernel, dev_get_valid_name was not called before register_netdevice. This allowed local users to cause a denial of service (NULL pointer dereference and panic) via an ioctl(TUNSETIFF) call with a dev name containing a / character. (bnc#1135603)
• CVE-2019-11190: The Linux kernel allowed local users to bypass ASLR on setuid programs (such as /bin/su) because install_exec_creds() was called too late in load_elf_binary() in fs/binfmt_elf.c, and thus the ptrace_may_access() check had a race condition when reading /proc/pid/stat. (bnc#1132472)
• CVE-2019-11815: An issue was discovered in rds_tcp_kill_sock in net/rds/tcp.c in the Linux kernel There was a race condition leading to a use-after-free, related to net namespace cleanup. (bnc#1134537)
• CVE-2019-11884: The do_hidp_sock_ioctl function in net/bluetooth/hidp/sock.c in the Linux kernel allowed a local user to obtain potentially sensitive information from kernel stack memory via a HIDPCONNADD command, because a name field may not end with a '\0' character. (bnc#1134848)
• CVE-2018-17972: An issue was discovered in the proc_pid_stack function in fs/proc/base.c in the Linux kernel It did not ensure that only root may inspect the kernel stack of an arbitrary task, allowing a local attacker to exploit racy stack unwinding and leak kernel task stack contents. (bnc#1110785)
• CVE-2019-11486: The Siemens R3964 line discipline driver in drivers/tty/n_r3964.c in the Linux kernel had multiple race conditions. (bnc#1133188)

The following non-security bugs were fixed:

• 9p locks: add mount option for lock retry interval (bnc#1012382).
• 9p: do not trust pdu content for stat item size (bnc#1012382).
• X.509: unpack RSA signatureValue field from BIT STRING (git-fixes).
• acpi / sbs: Fix GPE storm on recent MacBookPro's (bnc#1012382).
• alsa: core: Fix card races between register and disconnect (bnc#1012382).
• alsa:…

The SUSE Linux Enterprise 12 SP1 kernel version 3.12.74 was updated to to receive various security and bugfixes.

The following security bugs were fixed:

• CVE-2019-11477: A sequence of SACKs may have been crafted by a remote attacker such that one can trigger an integer overflow, leading to a kernel panic. (bsc#1137586).

• CVE-2019-11478: It is possible to send a crafted sequence of SACKs which will fragment the TCP retransmission queue. A remote attacker may be able to further exploit the fragmented queue to cause an expensive linked-list walk for subsequent SACKs received for that same TCP connection.

• CVE-2019-11479: It was possible to send a crafted sequence of SACKs which will fragment the RACK send map. A remote attacker may be able to further exploit the fragmented send map to cause an expensive linked-list walk for subsequent SACKs received for that same TCP connection. This would have resulted in excess resource consumption due to low mss values.

• CVE-2019-3846: A flaw that allowed an attacker to corrupt memory and possibly escalate privileges was found in the mwifiex kernel module while connecting to a malicious wireless network. (bnc#1136424)

• CVE-2019-5489: The mincore() implementation in mm/mincore.c in the Linux kernel allowed local attackers to observe page cache access patterns of other processes on the same system, potentially allowing sniffing of secret information. (Fixing this affects the output of the fincore program.) Limited remote exploitation may be possible, as demonstrated by latency differences in accessing public files from an Apache HTTP Server. (bnc#1120843)

• CVE-2019-11833: fs/ext4/extents.c in the Linux kernel did not zero out the unused memory region in the extent tree block, which might allow local users to obtain sensitive information by reading uninitialized data in the filesystem. (bnc#1135281)

• CVE-2019-11190: The Linux kernel allowed local users to bypass ASLR on setuid programs (such as /bin/su) because install_exec_creds() is called too late in load_elf_binary() in fs/binfmt_elf.c, and thus the ptrace_may_access() check has a race condition when reading /proc/pid/stat. (bnc#1131543)

• CVE-2019-11884: The do_hidp_sock_ioctl function in net/bluetooth/hidp/sock.c in the Linux kernel allowed a local user to obtain potentially sensitive information from kernel stack memory via a HIDPCONNADD command, because a name field may not end with a '\0' character. (bnc#1134848)

• CVE-2018-17972: An issue was discovered in the proc_pid_stack function in fs/proc/base.c in the Linux kernel It did not ensure that only root may inspect the kernel stack of an arbitrary task, allowing a local attacker to exploit racy stack unwinding and leak kernel task stack contents. (bnc#1110785)

The following non-security bugs were fixed:

• kabi: drop LINUX_MIB_TCPWQUEUETOOBIG snmp counter (bsc#1137586).
• kvm: x86: Fix the duplicated failure path handling in vmx_init (bsc#1104367).
• lib: add 'on'/'off' support to strtobool (bsc#1125931).
• powerpc/tm: Add commandline option to disable hardware transactional memory (bsc#1125580).
• powerpc/tm: Add TM Unavailable Exception (bsc#1125580).
• powerpc/tm: Flip the HTM switch default to disabled (bsc#1125580).
• powerpc/vdso32: fix CLOCK_MONOTONIC on PPC64 (bsc#1131587).
• powerpc/vdso64: Fix CLOCK_MONOTONIC inconsistencies across Y2038 (bsc#1131587).
• tcp: add tcp_min_snd_mss sysctl (bsc#1137586).
• tcp: enforce tcp_min_snd_mss in tcp_mtu_probing() (bsc#1137586).
• tcp: limit payload size of sacked skbs (bsc#1137586).
• tcp: tcp_fragment() should apply sane memory limits (bsc#1137586).

The SUSE Linux Enterprise 12 SP2 kernel version 4.4.121 was updated to receive various security and bugfixes.

The following security bugs were fixed:

• CVE-2019-11477: A sequence of SACKs may have been crafted by a remote attacker such that one can trigger an integer overflow, leading to a kernel panic. (bsc#1137586).

• CVE-2019-11478: It was possible to send a crafted sequence of SACKs which would fragment the TCP retransmission queue. A remote attacker may have been able to further exploit the fragmented queue to cause an expensive linked-list walk for subsequent SACKs received for that same TCP connection.

• CVE-2019-11479: It was possible to send a crafted sequence of SACKs which would fragment the RACK send map. A remote attacker may be able to further exploit the fragmented send map to cause an expensive linked-list walk for subsequent SACKs received for that same TCP connection. This would have resulted in excess resource consumption due to low mss values.

• CVE-2019-3846: A flaw that allowed an attacker to corrupt memory and possibly escalate privileges was found in the mwifiex kernel module while connecting to a malicious wireless network. (bnc#1136424)

• CVE-2019-12382: An issue was discovered in drm_load_edid_firmware in drivers/gpu/drm/drm_edid_load.c in the Linux kernel There is an unchecked kstrdup of fwstr, which may have allowed an attacker to cause a denial of service (NULL pointer dereference and system crash). (bnc#1136586)

• CVE-2019-5489: The mincore() implementation in mm/mincore.c in the Linux kernel allowed local attackers to observe page cache access patterns of other processes on the same system, potentially allowing sniffing of secret information. (Fixing this affects the output of the fincore program.) Limited remote exploitation may have been possible, as demonstrated by latency differences in accessing public files from an Apache HTTP Server. (bnc#1120843)

• CVE-2019-11833: fs/ext4/extents.c in the Linux kernel did not zero out the unused memory region in the extent tree block, which might have allowed local users to obtain sensitive information by reading uninitialized data in the filesystem. (bnc#1135281)

• CVE-2018-7191: In the tun subsystem in the Linux kernel, dev_get_valid_name was not called before register_netdevice. This allowed local users to cause a denial of service (NULL pointer dereference and panic) via an ioctl(TUNSETIFF) call with a dev name containing a / character. This is similar to CVE-2013-4343. (bnc#1135603)

• CVE-2019-11190: The Linux kernel allowed local users to bypass ASLR on setuid programs (such as /bin/su) because install_exec_creds() is called too late in load_elf_binary() in fs/binfmt_elf.c, and thus the ptrace_may_access() check had a race condition when reading /proc/pid/stat. (bnc#1131543)

• CVE-2019-11815: An issue was discovered in rds_tcp_kill_sock in net/rds/tcp.c in the Linux kernel There was a race condition leading to a use-after-free, related to net namespace cleanup. (bnc#1134537)

• CVE-2019-11884: The do_hidp_sock_ioctl function in net/bluetooth/hidp/sock.c in the Linux kernel allowed a local user to obtain potentially sensitive information from kernel stack memory via a HIDPCONNADD command, because a name field may not have ended with a '\0' character. (bnc#1134848)

• CVE-2018-17972: An issue was discovered in the proc_pid_stack function in fs/proc/base.c in the Linux kernel It did not ensure that only root may inspect the kernel stack of an arbitrary task, allowing a local attacker to exploit racy stack unwinding and leak kernel task stack contents. (bnc#1110785)

The following non-security bugs were fixed:

• cifs: keep FileInfo handle live during oplock break (bsc#1106284, bsc#1131565).
• ftrace/x86_64: Emulate call function while updating in breakpoint handler (bsc#1099658).
• kabi: drop LINUX_MIB_TCPWQUEUETOOBIG snmp counter (bsc#1137586).
• kabi: move…

The SUSE Linux Enterprise 12 kernel version 3.12.61 was updated to receive various security and bugfixes.

The following security bugs were fixed:

• CVE-2019-11477: A sequence of SACKs may have been crafted by a remote attacker such that one can trigger an integer overflow, leading to a kernel panic. (bsc#1137586).

• CVE-2019-11478: It was possible to send a crafted sequence of SACKs which would fragment the TCP retransmission queue. A remote attacker may have been able to further exploit the fragmented queue to cause an expensive linked-list walk for subsequent SACKs received for that same TCP connection.

• CVE-2019-11479: It was possible to send a crafted sequence of SACKs which would fragment the RACK send map. A remote attacker may have been able to further exploit the fragmented send map to cause an expensive linked-list walk for subsequent SACKs received for that same TCP connection. This would have resulted in excess resource consumption due to low mss values.

• CVE-2019-3846: A flaw that allowed an attacker to corrupt memory and possibly escalate privileges was found in the mwifiex kernel module while connecting to a malicious wireless network. (bnc#1136424)

• CVE-2019-5489: The mincore() implementation in mm/mincore.c in the Linux kernel allowed local attackers to observe page cache access patterns of other processes on the same system, potentially allowing sniffing of secret information. (Fixing this affects the output of the fincore program.) Limited remote exploitation may have been possible, as demonstrated by latency differences in accessing public files from an Apache HTTP Server. (bnc#1120843)

• CVE-2019-11833: fs/ext4/extents.c in the Linux kernel did not zero out the unused memory region in the extent tree block, which might have allowed local users to obtain sensitive information by reading uninitialized data in the filesystem. (bnc#1135281)

• CVE-2019-11190: The Linux kernel allowed local users to bypass ASLR on setuid programs (such as /bin/su) because install_exec_creds() is called too late in load_elf_binary() in fs/binfmt_elf.c, and thus the ptrace_may_access() check has a race condition when reading /proc/pid/stat. (bnc#1131543)

• CVE-2019-11884: The do_hidp_sock_ioctl function in net/bluetooth/hidp/sock.c in the Linux kernel allowed a local user to obtain potentially sensitive information from kernel stack memory via a HIDPCONNADD command, because a name field may not end with a '\0' character. (bnc#1134848)

• CVE-2018-17972: An issue was discovered in the proc_pid_stack function in fs/proc/base.c in the Linux kernel It did not ensure that only root may inspect the kernel stack of an arbitrary task, allowing a local attacker to exploit racy stack unwinding and leak kernel task stack contents. (bnc#1110785)

The following non-security bugs were fixed:

• kabi: drop LINUX_MIB_TCPWQUEUETOOBIG snmp counter (bsc#1137586).
• lib: add 'on'/'off' support to strtobool (bsc#1125931).
• powerpc/tm: Add commandline option to disable hardware transactional memory (bsc#1125580).
• powerpc/tm: Add TM Unavailable Exception (bsc#1125580).
• powerpc/tm: Flip the HTM switch default to disabled (bsc#1125580).
• powerpc/vdso32: fix CLOCK_MONOTONIC on PPC64 (bsc#1131587).
• powerpc/vdso64: Fix CLOCK_MONOTONIC inconsistencies across Y2038 (bsc#1131587).
• tcp: add tcp_min_snd_mss sysctl (bsc#1137586).
• tcp: enforce tcp_min_snd_mss in tcp_mtu_probing() (bsc#1137586).
• tcp: limit payload size of sacked skbs (bsc#1137586).
• tcp: tcp_fragment() should apply sane memory limits (bsc#1137586).

Robert Święcki discovered that the Linux kernel did not properly apply Address Space Layout Randomization (ASLR) in some situations for setuid elf binaries. A local attacker could use this to improve the chances of exploiting an existing vulnerability in a setuid elf binary. (CVE-2019-11190)

It was discovered that a null pointer dereference vulnerability existed in the LSI Logic MegaRAID driver in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2019-11810)

It was discovered that a race condition leading to a use-after-free existed in the Reliable Datagram Sockets (RDS) protocol implementation in the Linux kernel. The RDS protocol is disabled via blocklist by default in Ubuntu. If enabled, a local attacker could use this to cause a denial of service system crash) or possibly execute arbitrary code. (CVE-2019-11815)

Federico Manuel Bento discovered that the Linux kernel did not properly apply Address Space Layout Randomization (ASLR) in some situations for setuid a.out binaries. A local attacker could use this to improve the chances of exploiting an existing vulnerability in a setuid a.out binary. (CVE-2019-11191)

As a hardening measure, this update disables a.out support.

USN-4008-1 fixed multiple security issues in the Linux kernel. This update provides the corresponding changes to AppArmor policy for correctly operating under the Linux kernel with fixes for CVE-2019-11190. Without these changes, some profile transitions may be unintentionally denied due to missing mmap ('m') rules.

Original advisory details:

Robert Święcki discovered that the Linux kernel did not properly apply Address Space Layout Randomization (ASLR) in some situations for setuid elf binaries. A local attacker could use this to improve the chances of exploiting an existing vulnerability in a setuid elf binary. (CVE-2019-11190)

It was discovered that a null pointer dereference vulnerability existed in the LSI Logic MegaRAID driver in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2019-11810)

It was discovered that a race condition leading to a use-after-free existed in the Reliable Datagram Sockets (RDS) protocol implementation in the Linux kernel. The RDS protocol is disabled via blocklist by default in Ubuntu. If enabled, a local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-11815)

Federico Manuel Bento discovered that the Linux kernel did not properly apply Address Space Layout Randomization (ASLR) in some situations for setuid a.out binaries. A local attacker could use this to improve the chances of exploiting an existing vulnerability in a setuid a.out binary. (CVE-2019-11191)

As a hardening measure, this update disables a.out support.

USN-4008-1 fixed vulnerabilities in the Linux kernel for Ubuntu 16.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 16.04 LTS for Ubuntu 14.04 ESM.

Robert Święcki discovered that the Linux kernel did not properly apply Address Space Layout Randomization (ASLR) in some situations for setuid elf binaries. A local attacker could use this to improve the chances of exploiting an existing vulnerability in a setuid elf binary. (CVE-2019-11190)

It was discovered that a null pointer dereference vulnerability existed in the LSI Logic MegaRAID driver in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2019-11810)

It was discovered that a race condition leading to a use-after-free existed in the Reliable Datagram Sockets (RDS) protocol implementation in the Linux kernel. The RDS protocol is disabled via blocklist by default in Ubuntu. If enabled, a local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-11815)

Federico Manuel Bento discovered that the Linux kernel did not properly apply Address Space Layout Randomization (ASLR) in some situations for setuid a.out binaries. A local attacker could use this to improve the chances of exploiting an existing vulnerability in a setuid a.out binary. (CVE-2019-11191)

As a hardening measure, this update disables a.out support.