CVE-2021-33033
The Linux kernel before 5.11.14 has a use-after-free in cipso_v4_genopt in net/ipv4/cipso_ipv4.c because the CIPSO and CALIPSO refcounting for the DOI definitions is mishandled, aka CID-ad5d07f4a9cd.
02 Description
The Linux kernel before 5.11.14 has a use-after-free in cipso_v4_genopt in net/ipv4/cipso_ipv4.c because the CIPSO and CALIPSO refcounting for the DOI definitions is mishandled, aka CID-ad5d07f4a9cd.
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- 0.57% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 46.9% of scored records. A rank, not a probability.
- NVD base score
- 7.8 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVD analysis status
- Analyzed. NVD last modified this record on 2026-08-05.
- Red Hat severity
- Moderate. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-05-14 22:57Z5 YR AGO
- Last updated
- 2024-08-03 23:42Z2 YR AGO
- Reserved
- 2021-05-14
- Assigning CNA
- mitre
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- CWE-416Use After FreeVariant
- Data version
- 5.1
- Document digest
- e64f0d3ebd0dc4d339988ad02c065e8af59c14c919abc453b55451162f00aa4b
05 Affected products
06 References
- cdn.kernel.orghttps://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.7
- syzkaller.appspot.comhttps://syzkaller.appspot.com/bug?id=96e7d345748d8814901c91cd92084ed04b46701e
- sites.google.comhttps://sites.google.com/view/syzscope/kasan-use-after-free-read-in-cipso_v4_genopt
- git.kernel.orghttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ad5d07f4a9cd671233ae20983848874731102c08
- git.kernel.orghttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1165affd484889d4986cf3b724318935a0b120d8
- cdn.kernel.orghttps://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.14
07 Fixed in
AlmaLinux 8
- kernel-tools-libs-devel Fixed in 4.18.0-348.el8
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 8
- kernel-tools-libs-devel Fixed in 4.18.0-348.el8
Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Debian 12
- linux Fixed in 5.10.24-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- linux Fixed in 5.10.24-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- linux Fixed in 5.10.24-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 16.04 LTS
- linux-hwe-edge No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- linux Fixed in 4.15.0-144.148
- linux-aws Fixed in 4.15.0-1103.110
- linux-aws-5.0 No fix yet
- linux-aws-5.3 No fix yet
- linux-aws-5.4 Fixed in 5.4.0-1048.50~18.04.1
- linux-azure No fix yet
- linux-azure-4.15 Fixed in 4.15.0-1115.128
- linux-azure-5.3 No fix yet
- linux-azure-5.4 Fixed in 5.4.0-1047.49~18.04.1
- linux-azure-edge No fix yet
- linux-dell300x Fixed in 4.15.0-1022.26
- linux-gcp No fix yet
- linux-gcp-4.15 Fixed in 4.15.0-1100.113
- linux-gcp-5.3 No fix yet
- linux-gcp-5.4 Fixed in 5.4.0-1043.46~18.04.1
- linux-gcp-edge No fix yet
- linux-gke-4.15 No fix yet
- linux-gke-5.4 Fixed in 5.4.0-1043.45~18.04.1
- linux-gkeop-5.4 Fixed in 5.4.0-1015.16~18.04.1
- linux-hwe No fix yet
- linux-hwe-5.4 Fixed in 5.4.0-73.82~18.04.1
- linux-hwe-edge No fix yet
- linux-kvm Fixed in 4.15.0-1092.94
- linux-oem No fix yet
- linux-oracle Fixed in 4.15.0-1072.80
- linux-oracle-5.0 No fix yet
- linux-oracle-5.3 No fix yet
- linux-oracle-5.4 Fixed in 5.4.0-1044.47~18.04.1
- linux-raspi-5.4 Fixed in 5.4.0-1035.38~18.04.1
- linux-raspi2 Fixed in 4.15.0-1086.91
- linux-snapdragon Fixed in 4.15.0-1103.112
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- linux Fixed in 5.4.0-73.82
- linux-aws Fixed in 5.4.0-1048.50
- linux-azure Fixed in 5.4.0-1047.49
- linux-gcp Fixed in 5.4.0-1043.46
- linux-gke Fixed in 5.4.0-1043.45
- linux-gkeop Fixed in 5.4.0-1015.16
- linux-hwe-5.8 Fixed in 5.8.0-55.62~20.04.1
- linux-kvm Fixed in 5.4.0-1039.40
- linux-oem-5.10 Fixed in 5.10.0-1021.22
- linux-oem-5.6 No fix yet
- linux-oracle Fixed in 5.4.0-1045.49
- linux-raspi Fixed in 5.4.0-1035.38
- linux-raspi2 No fix yet
- linux-riscv No fix yet
- linux-riscv-5.8 Fixed in 5.8.0-26.28~20.04.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- linux-intel-iot-realtime No fix yet
- linux-realtime No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- linux-raspi-realtime No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- linux No fix yet
- linux-aws Fixed in 4.4.0-1102.107Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-azure Fixed in 4.15.0-1115.128~14.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-lts-xenial Fixed in 4.4.0-222.255~14.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 16.04 LTS
- linux Fixed in 4.4.0-222.255Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-aws Fixed in 4.4.0-1138.152Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-aws-hwe Fixed in 4.15.0-1103.110~16.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-azure Fixed in 4.15.0-1115.128~16.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-gcp Fixed in 4.15.0-1100.113~16.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-hwe Fixed in 4.15.0-144.148~16.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-kvm Fixed in 4.4.0-1103.112Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-oracle Fixed in 4.15.0-1072.80~16.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS-updates 16.04 LTS
- linux-fips Fixed in 4.4.0-1072.78Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS-updates 18.04 LTS
- linux-aws-fips Fixed in 4.15.0-2045.47Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-azure-fips Fixed in 4.15.0-2027.30Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-fips Fixed in 4.15.0-1060.68Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS-updates 20.04 LTS
- linux-aws-fips Fixed in 5.4.0-1069.73+fips2Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-azure-fips Fixed in 5.4.0-1073.76+fips1Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-gcp-fips Fixed in 5.4.0-1067.71~20.04.1Available with Ubuntu Pro: https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS 16.04 LTS
- linux-fips No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS 18.04 LTS
- linux-aws-fips No fix yet
- linux-azure-fips No fix yet
- linux-fips No fix yet
- linux-gcp-fips No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro FIPS 20.04 LTS
- linux-aws-fips No fix yet
- linux-azure-fips No fix yet
- linux-fips No fix yet
- linux-gcp-fips No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.