CVE-2019-19126

On the x86-64 architecture, the GNU C Library (aka glibc) before 2.31 fails to ignore the LD_PREFER_MAP_32BIT_EXEC environment variable during program execution after a security transition, allowing local attackers to restrict the possible mapping addresses for loaded libraries and thus bypass ASLR for a setuid program.

On the x86-64 architecture, the GNU C Library (aka glibc) before 2.31 fails to ignore the LD_PREFER_MAP_32BIT_EXEC environment variable during program execution after a security transition, allowing local attackers to restrict the possible mapping addresses for loaded libraries and thus bypass ASLR for a setuid program.

Updated glibc packages fixes the following security issue:

On the x86-64 architecture, the GNU C Library (aka glibc) before 2.31 fails to ignore the LD_PREFER_MAP_32BIT_EXEC environment variable during program execution after a security transition, allowing local attackers to restrict the possible mapping addresses for loaded libraries and thus bypass ASLR for a setuid program (CVE-2019-19126).

Other upstream fixes in this update:

• Call _dl_open_check after relocation [BZ #24259]
• support: Export bindir path on support_path
• nss_db: fix endent wrt NULL mappings [BZ #24695] [BZ #24696]
• elf: Refuse to dlopen PIE objects [BZ #24323]
• Fix alignment of TLS variables for tls variant TLS_TCB_AT_TP [BZ #23403]
• Fix assertion in malloc.c:tcache_get
• Small tcache improvements
• malloc: Remove unwanted leading whitespace in malloc_info [BZ #24867]
• malloc: Fix missing accounting of top chunk in malloc_info [BZ #24026]
• Add glibc.malloc.mxfast tunable
• malloc: Various cleanups for malloc/tst-mxfast
• Base max_fast on alignment, not width, of bins [BZ #24903]
• Linux: Use in-tree copy of SO_ constants for !__USE_MISC [BZ #24532]

These are all security issues fixed in the glibc-2.34-1.2 package on the GA media of openSUSE Tumbleweed.

This update for glibc fixes the following issues:

Security issue fixed:

• CVE-2019-19126: Fixed to ignore the LD_PREFER_MAP_32BIT_EXEC environment variable during program execution after a security transition (bsc#1157292).

Bug fixes:

• Fixed z15 (s390x) strstr implementation that can return incorrect results if search string cross page boundary (bsc#1157893).
• Fixed Hardware support in toolchain (bsc#1151582).
• Fixed syscalls during early process initialization (SLE-8348).
• Fixed an array overflow in backtrace for PowerPC (bsc#1158996).
• Moved to posix_spawn on popen (bsc#1149332).

Florian Weimer discovered that the GNU C Library incorrectly handled certain memory operations. A remote attacker could use this issue to cause the GNU C Library to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 16.04 LTS. (CVE-2017-12133)

It was discovered that the GNU C Library incorrectly handled certain SSE2-optimized memmove operations. A remote attacker could use this issue to cause the GNU C Library to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 16.04 LTS. (CVE-2017-18269)

It was discovered that the GNU C Library incorrectly handled certain pathname operations. A remote attacker could use this issue to cause the GNU C Library to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 18.04 LTS. (CVE-2018-11236)

It was discovered that the GNU C Library incorrectly handled certain AVX-512-optimized mempcpy operations. A remote attacker could use this issue to cause the GNU C Library to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 18.04 LTS. (CVE-2018-11237)

It was discovered that the GNU C Library incorrectly handled certain hostname loookups. A remote attacker could use this issue to cause the GNU C Library to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 18.04 LTS. (CVE-2018-19591)

Jakub Wilk discovered that the GNU C Library incorrectly handled certain memalign functions. A remote attacker could use this issue to cause the GNU C Library to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 16.04 LTS. (CVE-2018-6485)

It was discovered that the GNU C Library incorrectly ignored the LD_PREFER_MAP_32BIT_EXEC environment variable after security transitions. A local attacker could use this issue to bypass ASLR restrictions. (CVE-2019-19126)

It was discovered that the GNU C Library incorrectly handled certain regular expressions. A remote attacker could possibly use this issue to cause the GNU C Library to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2019-9169)

It was discovered that the GNU C Library incorrectly handled certain bit patterns. A remote attacker could use this issue to cause the GNU C Library to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2020-10029)

It was discovered that the GNU C Library incorrectly handled certain signal trampolines on PowerPC. A remote attacker could use this issue to cause the GNU C Library to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2020-1751)

It was discovered that the GNU C Library incorrectly handled tilde expansion. A remote attacker could use this issue to cause the GNU C Library to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2020-1752)