CVE intelligence and bounded remediation

CVE-2021-20265 — A flaw was found in the way memory resources were freed in the unix_stream_recvmsg function in the Linux kernel when a signal was pending

Medium CVSS 5.5

A flaw was found in the way memory resources were freed in the unix_stream_recvmsg function in the Linux kernel when a signal was pending. This flaw allows an unprivileged local user to crash the system by exhausting available memory. The highest threat from this vulnerability is to system availability.

Severity
Medium
CVSS
5.5 (3.1)
Published
2021-03-10
CISA KEV
Not currently listed
Ecosystem
linux/kernel
Weaknesses
CWE-400, CWE-401

Affected products

  • linux / linux_kernel
  • oracle / tekelec_platform_distribution

Matched remediation archetype

Resource exhaustion and denial of service

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify attacker-influenced work factors including input size, nesting, compression, fan-out, regex cost, allocation, recursion, retries, and connection lifetime.
  • Map per-request and shared CPU, memory, disk, descriptor, thread, queue, and downstream-service limits.
  • Determine whether authentication, tenancy, quotas, and rate controls apply before expensive processing begins.

Remediate safely

  • Bound input size, nesting, expansion, work, concurrency, queue depth, retries, and execution time before resource-intensive processing.
  • Release resources on every success, error, cancellation, and timeout path and use backpressure instead of unbounded buffering.
  • Update affected components and add small deterministic tests that assert resource ceilings rather than exhausting a host.

Authoritative sources

Complete CVE record and remediation plan

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