Vulnerability in Cisco Adaptive Security Appliance (ASA) Software (CVE-2020-3561)
Summary
Vulnerability in Cisco Adaptive Security Appliance (ASA) Software (CVE-2020-3561). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
A vulnerability in the Clientless SSL VPN (WebVPN) of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to inject arbitrary HTTP headers in the responses of the affected system. The vulnerability is due to improper input sanitization. An attacker could exploit this vulnerability by persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to conduct a CRLF injection attack, adding arbitrary HTTP headers in the responses of the system and redirecting the user to arbitrary websites.
Source: NIST National Vulnerability Database NVD
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-2020-3561 has been found in Cisco Adaptive Security Appliance (ASA) Software.
Risk of unauthorized operations or information disclosure. CVSS score: 4.7/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Cisco Adaptive Security Appliance (ASA) Software CVE-2020-3561" on the vendor's site.
CVE-2020-3561 (Cisco Adaptive Security Appliance (ASA) Software) — CWE-93 / CVSS v3 4.7
Attack vector: remote (network-reachable) / unauthenticated
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-93) exists in Cisco Adaptive Security Appliance (ASA) Software.
Check the vendor advisory for the affected versions of Cisco Adaptive Security Appliance (ASA) Software.
Severity: Medium (CVSS 4.7/10). Risk of unauthorized operations or information disclosure.
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 Cisco Adaptive Security Appliance (ASA) Software 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。
References
- patch tools.cisco.com