Vulnerability in Linux Kernel (CVE-2021-23133)
Summary
Vulnerability in Linux Kernel (CVE-2021-23133). Successful exploitation can lead to full system takeover.
Original description
The description as published by the source.
A race condition in Linux kernel SCTP sockets (net/sctp/socket.c) before 5.12-rc8 can lead to kernel privilege escalation from the context of a network service or an unprivileged process. If sctp_destroy_sock is called without sock_net(sk)->sctp.addr_wq_lock then an element is removed from the auto_asconf_splist list without any proper locking. This can be exploited by an attacker with network service privileges to escalate to root or from the context of an unprivileged user directly if a BPF_CGROUP_INET_SOCK_CREATE is attached which denies creation of some SCTP socket.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2021-23133 has been found in Linux Kernel.
Successful exploitation can lead to full system takeover. CVSS score: 6.7/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux Kernel CVE-2021-23133" on the vendor's site.
CVE-2021-23133 (Linux Kernel) — CWE-362 / CVSS v3 6.7
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-362) exists in Linux Kernel.
Check the vendor advisory for the affected versions of Linux Kernel.
Severity: Medium (CVSS 6.7/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux Kernel を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2021-23133 linux Fixed in: 5.10.38-1
- Ubuntu UBUNTU-CVE-2021-23133 linux-azure Fixed in: 4.15.0-1118.131~14.04.1
References
- advisory lists.debian.org
- advisory lists.debian.org
- advisory lists.fedoraproject.org
- advisory lists.fedoraproject.org
- advisory lists.fedoraproject.org
- advisory security.netapp.com
- exploit openwall.com
- patch git.kernel.org
- patch openwall.com
- patch openwall.com
- patch openwall.com
- patch openwall.com
- web nvd.nist.gov
- web lists.fedoraproject.org
- web lists.fedoraproject.org
- web lists.fedoraproject.org
- web lists.fedoraproject.org
- web lists.fedoraproject.org
- web lists.fedoraproject.org
- web security.netapp.com
- web github.com