CVE-2021-43057
An issue was discovered in the Linux kernel before 5.14.8. A use-after-free in...
An issue was discovered in the Linux kernel before 5.14.8. A use-after-free in selinux_ptrace_traceme (aka the SELinux handler for PTRACE_TRACEME) could be used by local attackers to cause memory corruption and escalate privileges, aka CID-a3727a8bac0a. This occurs because of an attempt to access the subjective credentials of another task.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
7.8
An issue was discovered in the Linux kernel before 5.14.8. A use-after-free in selinux_ptrace_traceme (aka the SELinux handler for PTRACE_TRACEME) could be used by local attackers to cause memory corruption and escalate privileges, aka CID-a3727a8bac0a. This occurs because of an attempt to access the subjective credentials of another task.
- Record
CVE-2021-43057- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.2 High
AV:L/AC:L/Au:N/C:C/I:C/A:C - Weakness
- CWE-416
- Updated
- 2026-11-02
CVE List No score
An issue was discovered in the Linux kernel before 5.14.8. A use-after-free in selinux_ptrace_traceme (aka the SELinux handler for PTRACE_TRACEME) could be used by local attackers to cause memory corruption and escalate privileges, aka CID-a3727a8bac0a. This occurs because of an attempt to access the subjective credentials of another task.
- Record
CVE-2021-43057- Updated
- 2026-11-02
EUVDEUVD-2021-30010 No score
An issue was discovered in the Linux kernel before 5.14.8. A use-after-free in selinux_ptrace_traceme (aka the SELinux handler for PTRACE_TRACEME) could be used by local attackers to cause memory corruption and escalate privileges, aka CID-a3727a8bac0a. This occurs because of an attempt to access the subjective credentials of another task.
- Record
EUVD-2021-30010- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-h3xq-35q6-gh9g
7.8
An issue was discovered in the Linux kernel before 5.14.8. A use-after-free in...
An issue was discovered in the Linux kernel before 5.14.8. A use-after-free in selinux_ptrace_traceme (aka the SELinux handler for PTRACE_TRACEME) could be used by local attackers to cause memory corruption and escalate privileges, aka CID-a3727a8bac0a. This occurs because of an attempt to access the subjective credentials of another task.
- Record
GHSA-h3xq-35q6-gh9g- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-416
- Updated
- 2026-11-02
OSVAZL-6602
7.8
CVE-2021-43057 affecting package kernel for versions less than 5.15.2.1-1
An issue was discovered in the Linux kernel before 5.14.8. A use-after-free in selinux_ptrace_traceme (aka the SELinux handler for PTRACE_TRACEME) could be used by local attackers to cause memory corruption and escalate privileges, aka CID-a3727a8bac0a. This occurs because of an attempt to access the subjective credentials of another task.
- Record
AZL-6602- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSV
7.8
An issue was discovered in the Linux kernel before 5.14.8. A use-after-free in selinux_ptrace_traceme (aka the SELinux handler for PTRACE_TRACEME) could be used by local attackers to cause memory corruption and escalate privileges, aka CID-a3727a8bac0a. This occurs because of an attempt to access the subjective credentials of another task.
- Record
CVE-2021-43057- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-43057
7.8
An issue was discovered in the Linux kernel before 5.14.8. A use-after-free in selinux_ptrace_traceme (aka the SELinux handler for PTRACE_TRACEME) could be used by local attackers to cause memory corruption and escalate privileges, aka CID-a3727a8bac0a. This occurs because of an attempt to access the subjective credentials of another task.
- Record
DEBIAN-CVE-2021-43057- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-43057
7.8
An issue was discovered in the Linux kernel before 5.14.8. A use-after-free in selinux_ptrace_traceme (aka the SELinux handler for PTRACE_TRACEME) could be used by local attackers to cause memory corruption and escalate privileges, aka CID-a3727a8bac0a. This occurs because of an attempt to access the subjective credentials of another task.
- Record
UBUNTU-CVE-2021-43057- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUSN-5162-1 No score
linux, linux-aws, linux-azure, linux-gcp, linux-kvm, linux-oem-5.13, linux-oracle, linux-raspi vulnerabilities
Ilja Van Sprundel discovered that the SCTP implementation in the Linux kernel did not properly perform size validations on incoming packets in some situations. An attacker could possibly use this to expose sensitive information (kernel memory). (CVE-2021-3655)
It was discovered that the AMD Cryptographic Coprocessor (CCP) driver in the Linux kernel did not properly deallocate memory in some error conditions. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2021-3744, CVE-2021-3764)
It was discovered that the Aspeed Low Pin Count (LPC) Bus Controller implementation in the Linux kernel did not properly perform boundary checks in some situations, allowing out-of-bounds write access. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. In Ubuntu, this issue only affected systems running armhf kernels. (CVE-2021-42252)
Jann Horn discovered that the SELinux subsystem in the Linux kernel did not properly handle subjective credentials for tasks in some situations. On systems where SELinux has been enabled, a local attacker could possibly use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2021-43057)
- Record
USN-5162-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
kernelAzure Linux:2 |
before 5.15.2.1-1 | 5.15.2.1-1 |
linuxDebian:12 |
before 5.14.9-1 | 5.14.9-1 |
linuxDebian:13 |
before 5.14.9-1 | 5.14.9-1 |
linuxDebian:14 |
before 5.14.9-1 | 5.14.9-1 |
linux-hwe-edgeUbuntu:16.04:LTS |
All versions, plus listed versions 4.8.0-28.30~16.04.14.8.0-30.32~16.04.14.8.0-32.34~16.04.14.8.0-34.36~16.04.14.10.0-14.16~16.04.1 Show 18 moreShow less4.10.0-19.21~16.04.14.10.0-20.22~16.04.14.10.0-21.23~16.04.14.10.0-22.24~16.04.14.10.0-24.28~16.04.14.10.0-26.30~16.04.14.11.0-13.19~16.04.14.11.0-14.20~16.04.14.13.0-16.19~16.04.34.13.0-17.20~16.04.14.13.0-19.22~16.04.14.13.0-21.24~16.04.14.13.0-25.29~16.04.24.15.0-13.14~16.04.14.15.0-15.16~16.04.14.15.0-20.21~16.04.14.15.0-22.24~16.04.14.15.0-23.25~16.04.1 |
None known |
linux-aws-5.0Ubuntu:18.04:LTS |
All versions, plus listed versions 5.0.0-1021.24~18.04.15.0.0-1022.25~18.04.15.0.0-1023.26~18.04.15.0.0-1024.27~18.04.15.0.0-1025.285.0.0-1027.30 |
None known |
linux-aws-5.3Ubuntu:18.04:LTS |
All versions, plus listed versions 5.3.0-1016.17~18.04.15.3.0-1017.18~18.04.15.3.0-1019.21~18.04.15.3.0-1023.25~18.04.15.3.0-1028.30~18.04.1 Show 5 moreShow less5.3.0-1030.32~18.04.15.3.0-1032.34~18.04.25.3.0-1033.355.3.0-1034.365.3.0-1035.37 |
None known |
linux-azureUbuntu:18.04:LTS |
All versions, plus listed versions 4.15.0-1002.24.15.0-1003.34.15.0-1004.44.15.0-1008.84.15.0-1009.9 Show 39 moreShow less4.15.0-1012.124.15.0-1013.134.15.0-1014.144.15.0-1018.184.15.0-1019.194.15.0-1021.214.15.0-1022.234.15.0-1023.244.15.0-1025.264.15.0-1028.294.15.0-1030.314.15.0-1031.324.15.0-1032.334.15.0-1035.364.15.0-1036.384.15.0-1037.394.18.0-1011.11~18.04.14.18.0-1013.13~18.04.14.18.0-1014.14~18.04.14.18.0-1018.18~18.04.14.18.0-1019.19~18.04.14.18.0-1020.20~18.04.14.18.0-1023.24~18.04.14.18.0-1024.25~18.04.14.18.0-1025.27~18.04.15.0.0-1014.14~18.04.15.0.0-1016.17~18.04.15.0.0-1018.19~18.04.15.0.0-1020.21~18.04.15.0.0-1022.23~18.04.15.0.0-1023.24~18.04.15.0.0-1025.27~18.04.15.0.0-1027.29~18.04.15.0.0-1028.30~18.04.15.0.0-1029.31~18.04.15.0.0-1031.335.0.0-1032.345.0.0-1035.375.0.0-1036.38 |
None known |
linux-azure-5.3Ubuntu:18.04:LTS |
All versions, plus listed versions 5.3.0-1007.8~18.04.15.3.0-1008.9~18.04.15.3.0-1009.10~18.04.15.3.0-1010.11~18.04.15.3.0-1012.13~18.04.1 Show 11 moreShow less5.3.0-1013.14~18.04.15.3.0-1016.17~18.04.15.3.0-1018.19~18.04.15.3.0-1019.20~18.04.15.3.0-1020.21~18.04.15.3.0-1022.23~18.04.15.3.0-1028.29~18.04.15.3.0-1031.32~18.04.15.3.0-1032.33~18.04.15.3.0-1034.35~18.04.15.3.0-1035.36 |
None known |
linux-azure-edgeUbuntu:18.04:LTS |
All versions, plus listed versions 4.18.0-1006.6~18.04.14.18.0-1007.7~18.04.14.18.0-1008.8~18.04.15.0.0-1012.12~18.04.2 |
None known |
Show 21 moreShow less
| Package | Affected | Fixed |
|---|---|---|
linux-gcpUbuntu:18.04:LTS |
All versions, plus listed versions 4.15.0-1001.14.15.0-1003.34.15.0-1005.54.15.0-1006.64.15.0-1008.8 Show 33 moreShow less4.15.0-1009.94.15.0-1010.104.15.0-1014.144.15.0-1015.154.15.0-1017.184.15.0-1018.194.15.0-1019.204.15.0-1021.224.15.0-1023.244.15.0-1024.254.15.0-1025.264.15.0-1026.274.15.0-1027.284.15.0-1028.294.15.0-1029.314.15.0-1030.324.15.0-1032.344.15.0-1033.354.15.0-1034.364.15.0-1036.384.15.0-1037.394.15.0-1040.424.15.0-1042.454.15.0-1044.705.0.0-1020.20~18.04.15.0.0-1021.21~18.04.15.0.0-1025.26~18.04.15.0.0-1026.27~18.04.15.0.0-1028.29~18.04.15.0.0-1029.30~18.04.15.0.0-1031.325.0.0-1033.345.0.0-1034.35 |
None known |
linux-gcp-5.3Ubuntu:18.04:LTS |
All versions, plus listed versions 5.3.0-1008.9~18.04.15.3.0-1009.10~18.04.15.3.0-1010.11~18.04.15.3.0-1012.13~18.04.15.3.0-1014.15~18.04.1 Show 8 moreShow less5.3.0-1016.17~18.04.15.3.0-1017.18~18.04.15.3.0-1018.19~18.04.15.3.0-1020.22~18.04.15.3.0-1026.28~18.04.15.3.0-1029.31~18.04.15.3.0-1030.32~18.04.15.3.0-1032.34~18.04.1 |
None known |
linux-gke-4.15Ubuntu:18.04:LTS |
All versions, plus listed versions 4.15.0-1030.324.15.0-1032.344.15.0-1033.354.15.0-1034.364.15.0-1036.38 Show 28 moreShow less4.15.0-1037.394.15.0-1040.424.15.0-1041.434.15.0-1042.444.15.0-1044.464.15.0-1045.484.15.0-1046.494.15.0-1048.514.15.0-1049.524.15.0-1050.534.15.0-1052.554.15.0-1055.584.15.0-1057.604.15.0-1058.614.15.0-1059.624.15.0-1063.664.15.0-1064.674.15.0-1066.694.15.0-1067.704.15.0-1069.724.15.0-1070.734.15.0-1072.764.15.0-1073.784.15.0-1074.794.15.0-1076.814.15.0-1077.824.15.0-1078.834.15.0-1079.84 |
None known |
linux-hweUbuntu:18.04:LTS |
All versions, plus listed versions 4.18.0-13.14~18.04.14.18.0-14.15~18.04.14.18.0-15.16~18.04.14.18.0-16.17~18.04.14.18.0-17.18~18.04.1 Show 38 moreShow less4.18.0-18.19~18.04.14.18.0-20.21~18.04.14.18.0-21.22~18.04.14.18.0-22.23~18.04.14.18.0-24.25~18.04.14.18.0-25.26~18.04.15.0.0-23.24~18.04.15.0.0-25.26~18.04.15.0.0-27.28~18.04.15.0.0-29.31~18.04.15.0.0-31.33~18.04.15.0.0-32.34~18.04.25.0.0-35.38~18.04.15.0.0-36.39~18.04.15.0.0-37.40~18.04.15.3.0-26.28~18.04.15.3.0-28.30~18.04.15.3.0-40.32~18.04.15.3.0-42.34~18.04.15.3.0-45.37~18.04.15.3.0-46.38~18.04.15.3.0-51.44~18.04.25.3.0-53.47~18.04.15.3.0-59.53~18.04.15.3.0-61.55~18.04.15.3.0-62.56~18.04.15.3.0-64.58~18.04.15.3.0-65.595.3.0-66.605.3.0-67.615.3.0-68.635.3.0-69.655.3.0-70.665.3.0-72.685.3.0-73.695.3.0-74.705.3.0-75.715.3.0-76.72 |
None known |
linux-hwe-edgeUbuntu:18.04:LTS |
All versions, plus listed versions 5.0.0-15.16~18.04.15.0.0-16.17~18.04.15.0.0-17.18~18.04.15.0.0-19.20~18.04.15.0.0-20.21~18.04.1 Show 5 moreShow less5.3.0-19.20~18.04.25.3.0-22.24~18.04.15.3.0-23.25~18.04.15.3.0-23.25~18.04.25.3.0-24.26~18.04.2 |
None known |
linux-oemUbuntu:18.04:LTS |
All versions, plus listed versions 4.15.0-1002.34.15.0-1004.54.15.0-1006.94.15.0-1008.114.15.0-1009.12 Show 45 moreShow less4.15.0-1012.154.15.0-1013.164.15.0-1015.184.15.0-1017.204.15.0-1018.214.15.0-1021.244.15.0-1024.294.15.0-1026.314.15.0-1028.334.15.0-1030.354.15.0-1033.384.15.0-1034.394.15.0-1035.404.15.0-1036.414.15.0-1038.434.15.0-1039.444.15.0-1043.484.15.0-1045.504.15.0-1050.574.15.0-1056.654.15.0-1057.664.15.0-1059.684.15.0-1063.724.15.0-1064.734.15.0-1065.754.15.0-1066.764.15.0-1067.774.15.0-1069.794.15.0-1073.834.15.0-1076.864.15.0-1079.894.15.0-1080.904.15.0-1081.914.15.0-1087.974.15.0-1090.1004.15.0-1091.1014.15.0-1093.1034.15.0-1094.1044.15.0-1096.1064.15.0-1097.1074.15.0-1099.1094.15.0-1100.1104.15.0-1101.1124.15.0-1102.1134.15.0-1103.114 |
None known |
linux-oracle-5.0Ubuntu:18.04:LTS |
All versions, plus listed versions 5.0.0-1007.12~18.04.15.0.0-1008.13~18.04.15.0.0-1009.14~18.04.15.0.0-1010.15~18.04.15.0.0-1011.165.0.0-1013.185.0.0-1014.19 |
None known |
linux-oracle-5.3Ubuntu:18.04:LTS |
All versions, plus listed versions 5.3.0-1011.12~18.04.15.3.0-1013.14~18.04.15.3.0-1014.15~18.04.15.3.0-1016.18~18.04.15.3.0-1018.20~18.04.1 Show 4 moreShow less5.3.0-1024.26~18.04.15.3.0-1027.29~18.04.15.3.0-1028.30~18.04.15.3.0-1030.32~18.04.1 |
None known |
linux-hwe-5.13Ubuntu:20.04:LTS |
before 5.13.0-22.22~20.04.1, plus listed versions 5.13.0-21.21~20.04.1 |
5.13.0-22.22~20.04.1 |
linux-oem-5.13Ubuntu:20.04:LTS |
before 5.13.0-1020.24, plus listed versions 5.13.0-1009.105.13.0-1010.115.13.0-1012.165.13.0-1014.185.13.0-1017.215.13.0-1019.23 |
5.13.0-1020.24 |
linux-oem-5.14Ubuntu:20.04:LTS |
before 5.14.0-1005.5, plus listed versions 5.14.0-1004.4 |
5.14.0-1005.5 |
linux-aws-5.8Ubuntu:20.04:LTS |
All versions, plus listed versions 5.8.0-1035.37~20.04.15.8.0-1038.40~20.04.15.8.0-1041.43~20.04.15.8.0-1042.44~20.04.1 |
None known |
linux-azure-5.8Ubuntu:20.04:LTS |
All versions, plus listed versions 5.8.0-1033.35~20.04.15.8.0-1036.38~20.04.15.8.0-1039.42~20.04.15.8.0-1040.43~20.04.15.8.0-1041.44~20.04.15.8.0-1042.45~20.04.15.8.0-1043.46~20.04.1 |
None known |
linux-gcp-5.8Ubuntu:20.04:LTS |
All versions, plus listed versions 5.8.0-1032.34~20.04.15.8.0-1035.37~20.04.15.8.0-1038.40~20.04.15.8.0-1039.41 |
None known |
linux-intel-5.13Ubuntu:20.04:LTS |
All versions, plus listed versions 5.13.0-1007.75.13.0-1008.85.13.0-1009.95.13.0-1010.105.13.0-1011.115.13.0-1014.155.13.0-1017.19 |
None known |
linux-oem-5.6Ubuntu:20.04:LTS |
All versions, plus listed versions 5.6.0-1007.75.6.0-1008.85.6.0-1010.105.6.0-1011.115.6.0-1013.13 Show 24 moreShow less5.6.0-1017.175.6.0-1018.185.6.0-1020.205.6.0-1021.215.6.0-1023.235.6.0-1026.265.6.0-1027.275.6.0-1028.285.6.0-1031.325.6.0-1032.335.6.0-1033.355.6.0-1034.365.6.0-1035.375.6.0-1036.395.6.0-1039.435.6.0-1042.465.6.0-1047.515.6.0-1048.525.6.0-1050.545.6.0-1052.565.6.0-1053.575.6.0-1054.585.6.0-1055.595.6.0-1056.60 |
None known |
linux-oracle-5.8Ubuntu:20.04:LTS |
All versions, plus listed versions 5.8.0-1031.32~20.04.25.8.0-1033.34~20.04.15.8.0-1034.35~20.04.25.8.0-1037.38~20.04.15.8.0-1038.39~20.04.1 |
None known |
linux-raspi2Ubuntu:20.04:LTS |
All versions, plus listed versions 5.3.0-1007.85.3.0-1014.165.3.0-1015.175.3.0-1017.195.4.0-1004.45.4.0-1006.6 |
None known |
linux-riscvUbuntu:20.04:LTS |
All versions, plus listed versions 5.4.0-24.285.4.0-26.305.4.0-27.315.4.0-28.325.4.0-30.34 Show 7 moreShow less5.4.0-31.355.4.0-33.375.4.0-34.385.4.0-36.415.4.0-37.425.4.0-39.445.4.0-40.45 |
None known |
linux-riscv-5.8Ubuntu:20.04:LTS |
All versions, plus listed versions 5.8.0-14.16~20.04.15.8.0-14.16~20.04.35.8.0-16.18~20.04.15.8.0-17.19~20.04.15.8.0-18.20~20.04.1 Show 5 moreShow less5.8.0-20.22~20.04.15.8.0-22.24~20.04.15.8.0-25.27~20.04.15.8.0-26.28~20.04.15.8.0-29.31~20.04.1 |
None known |
linux-oem-5.13Ubuntu:20.04:LTS From an advisory covering 5 CVEs |
before 5.13.0-1020.24, plus listed versions 5.13.0-1009.105.13.0-1010.115.13.0-1012.165.13.0-1014.185.13.0-1017.215.13.0-1019.23 |
5.13.0-1020.24 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-43057 is a high vulnerability (CVSS 7.8) in Linux Kernel, published October 28, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.49%, the 42nd percentile. Fixed in kernel 5.15.2.1-1.
References
bugs.chromium.org/p/project-zero/issues/detail?id=2229
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=a3727a8bac0a9e77c70820655fd8715523ba3db7
cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.14.8
security.netapp.com/advisory/ntap-20211125-0001
nvd.nist.gov/vuln/detail/CVE-2021-43057
github.com/advisories/GHSA-h3xq-35q6-gh9g
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security-tracker.debian.org/tracker/CVE-2021-43057
ubuntu.com/security/CVE-2021-43057
git.kernel.org/linus/a3727a8bac0a9e77c70820655fd8715523ba3db7
ubuntu.com/security/notices/USN-5162-1
cve.org/CVERecord?id=CVE-2021-43057
ubuntu.com/security/CVE-2021-3655
ubuntu.com/security/CVE-2021-3744
ubuntu.com/security/CVE-2021-3764
ubuntu.com/security/CVE-2021-42252