CVE intelligence and bounded remediation

CVE-2021-1252 — Clamav Clamav security vulnerability

High CVSS 7.8

A vulnerability in the Excel XLM macro parsing module in Clam AntiVirus (ClamAV) Software versions 0.103.0 and 0.103.1 could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to improper error handling that may result in an infinite loop. An attacker could exploit this vulnerability by sending a crafted Excel file to an affected device. An exploit could allow the attacker to cause the ClamAV scanning process hang, resulting in a denial of service condition.

Severity
High
CVSS
7.8 (2.0)
Published
2021-04-08
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-20, CWE-835

Affected products

  • clamav / clamav / 0.103.0
  • clamav / clamav / 0.103.1

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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