CVE intelligence and bounded remediation

CVE-2025-20183 — Cisco Asyncos security vulnerability

Medium CVSS 5.8

A vulnerability in a policy-based Cisco Application Visibility and Control (AVC) implementation of Cisco AsyncOS Software for Cisco Secure Web Appliance could allow an unauthenticated, remote attacker to evade the antivirus scanner and download a malicious file onto an endpoint.  The vulnerability is due to improper handling of a crafted range request header. An attacker could exploit this vulnerability by sending an HTTP request with a crafted range request header through the affected device. A successful exploit could allow the attacker to evade the antivirus scanner and download malware onto the endpoint without detection by Cisco Secure Web Appliance.

Severity
Medium
CVSS
5.8 (3.1)
Published
2025-02-05
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-20

Affected products

  • cisco / asyncos / 11.8.0-414
  • cisco / asyncos / 11.8.0-429
  • cisco / asyncos / 11.8.0-453
  • cisco / asyncos / 11.8.1-023
  • cisco / asyncos / 11.8.3-018
  • cisco / asyncos / 11.8.3-021

Showing 6 representative product identities from 51 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

General vulnerability remediation

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

Check exposure

  • Confirm the affected component, deployment paths, reachable interfaces, and enabled features from inventories and configuration, without probing production destructively.
  • Compare the advisory's affected conditions with the repository lockfiles, build manifests, artifacts, and runtime inventory.
  • Identify data sensitivity, trust boundaries, and privilege level for every confirmed affected deployment.

Remediate safely

  • Apply a vendor-supported fix or remove the affected component or feature; record the selected change and its source in the repository.
  • Update direct and transitive dependency locks, generated artifacts, deployment manifests, and asset inventories together.
  • Add a regression test for the documented unsafe condition using inert inputs and preserve rollback instructions.

Authoritative sources

Complete CVE record and remediation plan

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