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UBUNTU-CVE-2021-45095
pep_sock_accept in net/phonet/pep.c in the Linux kernel through 5.15.8 has a refcount leak.
AI summary snake-internal / snake-template-v1
A weakness called UBUNTU-CVE-2021-45095 was discovered in the affected product.
Severity is Info. Low severity or not yet rated.
What you should do: update the affected software to the latest version. If unsure, ask your IT team or search the vendor's site for "the product UBUNTU-CVE-2021-45095".
UBUNTU-CVE-2021-45095 (the affected product). Severity: Info.
Response plan:
1. Check the vendor advisory for affected versions and the patched release.
2. If a vulnerable version is running in production, schedule maintenance (urgency from KEV/CVSS).
3. If no patch yet, mitigate via WAF rule, disabling the affected feature, etc.
4. Monitor logs / SIEM for known IOC and PoC signatures of this CVE.
PoCs and fix commits: see the 'References' section, MITRE, and NVD.
❓ What is the problem
A weakness (UBUNTU-CVE-2021-45095) in the affected product. A serious software flaw has been identified.
📍 Affected scope
Target versions of the affected product (see vendor advisory). If running in production, identify exposure immediately.
🔥 Severity
Severity: Info. Low severity or not yet rated.
🔧 How to fix
Update to the patched release as listed in the vendor advisory.
🛡️ Workaround
If a patch is not yet available, consider disabling the affected feature, applying WAF rules, blocking via network ACLs, or isolating the vulnerable version.
🔍 Detection
Check version information, scan dependencies via SBOM, and monitor SIEM for IOC and PoC signatures related to this CVE.
Affected packages
Ubuntu:Pro:14.04:LTS
linux-aws
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-1102.107"}]}]
Ubuntu:Pro:14.04:LTS
linux-azure
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1134.147~14.04.1"}]}]
Ubuntu:Pro:14.04:LTS
linux-lts-xenial
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-222.255~14.04.1"}]}]
Ubuntu:Pro:14.04:LTS
linux
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:16.04:LTS
linux
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-222.255"}]}]
Ubuntu:Pro:16.04:LTS
linux-aws
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-1138.152"}]}]
Ubuntu:Pro:16.04:LTS
linux-aws-hwe
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1124.133~16.04.1"}]}]
Ubuntu:Pro:16.04:LTS
linux-azure
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1134.147~16.04.1"}]}]
Ubuntu:Pro:16.04:LTS
linux-gcp
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1119.133~16.04.1"}]}]
Ubuntu:Pro:16.04:LTS
linux-hwe
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-173.182~16.04.1"}]}]
Ubuntu:16.04:LTS
linux-hwe-edge
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:16.04:LTS
linux-kvm
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.4.0-1103.112"}]}]
Ubuntu:Pro:16.04:LTS
linux-oracle
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1090.99~16.04.1"}]}]
Ubuntu:Pro:FIPS:16.04:LTS
linux-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-173.182"}]}]
Ubuntu:18.04:LTS
linux-aws
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1124.133"}]}]
Ubuntu:18.04:LTS
linux-aws-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1069.73~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-azure-4.15
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1134.147"}]}]
Ubuntu:18.04:LTS
linux-azure-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1073.76~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-dell300x
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1038.43"}]}]
Ubuntu:18.04:LTS
linux-gcp-4.15
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1119.133"}]}]
Ubuntu:18.04:LTS
linux-gcp-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1068.72~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-gke-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1066.69~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-gkeop-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1037.38~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-hwe-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-105.119~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-ibm-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1018.20~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-kvm
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1110.113"}]}]
Ubuntu:18.04:LTS
linux-oracle
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1090.99"}]}]
Ubuntu:18.04:LTS
linux-oracle-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1067.72~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-raspi-5.4
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1056.63~18.04.1"}]}]
Ubuntu:18.04:LTS
linux-raspi2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1106.113"}]}]
Ubuntu:18.04:LTS
linux-snapdragon
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1123.132"}]}]
Ubuntu:18.04:LTS
linux-aws-5.0
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-aws-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-azure
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-azure-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-azure-edge
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-gcp
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-gcp-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-gke-4.15
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-hwe
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-hwe-edge
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-oem
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-oracle-5.0
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:18.04:LTS
linux-oracle-5.3
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS-updates:18.04:LTS
linux-aws-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-2064.67"}]}]
Ubuntu:Pro:FIPS-updates:18.04:LTS
linux-azure-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-2046.50"}]}]
Ubuntu:Pro:FIPS-updates:18.04:LTS
linux-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-1081.90"}]}]
Ubuntu:Pro:FIPS-updates:18.04:LTS
linux-gcp-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.15.0-2029.32"}]}]
Ubuntu:Pro:FIPS:18.04:LTS
linux-aws-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:18.04:LTS
linux-azure-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:18.04:LTS
linux-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:18.04:LTS
linux-gcp-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-105.119"}]}]
Ubuntu:20.04:LTS
linux-aws
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1069.73"}]}]
Ubuntu:20.04:LTS
linux-aws-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.13.0-1019.21~20.04.1"}]}]
Ubuntu:20.04:LTS
linux-azure
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1073.76"}]}]
Ubuntu:20.04:LTS
linux-azure-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.13.0-1021.24~20.04.1"}]}]
Ubuntu:20.04:LTS
linux-bluefield
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1032.35"}]}]
Ubuntu:20.04:LTS
linux-gcp
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1068.72"}]}]
Ubuntu:20.04:LTS
linux-gcp-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.13.0-1021.25~20.04.1"}]}]
Ubuntu:20.04:LTS
linux-gke
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1066.69"}]}]
Ubuntu:20.04:LTS
linux-gkeop
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1037.38"}]}]
Ubuntu:20.04:LTS
linux-hwe-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.13.0-37.42~20.04.1"}]}]
Ubuntu:20.04:LTS
linux-ibm
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1018.20"}]}]
Ubuntu:20.04:LTS
linux-kvm
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1059.62"}]}]
Ubuntu:20.04:LTS
linux-oem-5.14
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.14.0-1022.24"}]}]
Ubuntu:20.04:LTS
linux-oracle
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1067.72"}]}]
Ubuntu:20.04:LTS
linux-oracle-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.13.0-1025.30~20.04.1"}]}]
Ubuntu:20.04:LTS
linux-raspi
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1056.63"}]}]
Ubuntu:20.04:LTS
linux-aws-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-aws-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-azure-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-azure-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-gcp-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-gcp-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-hwe-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-hwe-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-intel-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oem-5.10
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oem-5.13
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oem-5.6
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oracle-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-oracle-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-raspi2
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-riscv
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-riscv-5.11
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:20.04:LTS
linux-riscv-5.8
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS-updates:20.04:LTS
linux-aws-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1069.73+fips2"}]}]
Ubuntu:Pro:FIPS-updates:20.04:LTS
linux-azure-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1073.76+fips1"}]}]
Ubuntu:Pro:FIPS-updates:20.04:LTS
linux-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1046.52"}]}]
Ubuntu:Pro:FIPS-updates:20.04:LTS
linux-gcp-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.4.0-1067.71~20.04.1"}]}]
Ubuntu:Pro:FIPS:20.04:LTS
linux-aws-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:20.04:LTS
linux-azure-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:20.04:LTS
linux-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:Pro:FIPS:20.04:LTS
linux-gcp-fips
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-intel-iot-realtime
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:22.04:LTS
linux-realtime
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:24.04:LTS
linux-raspi-realtime
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
Ubuntu:26.04
linux-nvidia
[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]
References
- advisory https://ubuntu.com/security/notices/USN-5278-1
- advisory https://ubuntu.com/security/notices/USN-5337-1
- advisory https://ubuntu.com/security/notices/USN-5338-1
- advisory https://ubuntu.com/security/notices/USN-5339-1
- advisory https://ubuntu.com/security/notices/USN-5343-1
- advisory https://ubuntu.com/security/notices/USN-5368-1
- advisory https://ubuntu.com/security/notices/USN-5377-1
- report https://ubuntu.com/security/CVE-2021-45095
- report https://lore.kernel.org/all/[email protected]/
- report https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=bcd0f93353326954817a4f9fa55ec57fb38acbb0
- report https://github.com/torvalds/linux/commit/bcd0f93353326954817a4f9fa55ec57fb38acbb0
- report https://www.cve.org/CVERecord?id=CVE-2021-45095