CVE-2020-3118 — Cisco IOS XR Software Discovery Protocol Format String Vulnerability
Overview
Cisco IOS XR improperly validates string input from certain fields in Cisco Discovery Protocol messages. Exploitation could allow an unauthenticated, adjacent attacker to execute code with administrative privileges or cause a reload on an affected device.
Vulnerability details
- CVE ID
- CVE-2020-3118
- Vulnerability
- Cisco IOS XR Software Discovery Protocol Format String Vulnerability
- Vendor
- Cisco
- Affected products
- Cisco: IOS XR
- Severity
- HIGH
- Exploitation status
- Actively exploited in the wild (CISA KEV)
- Published
- 2021-11-03
Remediation guidance
CVE-2020-3118 is in CISA's Known Exploited Vulnerabilities (KEV) catalog — U.S. federal civilian agencies are required to remediate it under Binding Operational Directive 22-01. Treat it as a priority for every environment.
Apply the vendor's official security update for Cisco the affected product as soon as possible. Where a patch is unavailable, apply vendor mitigations or isolate/segment exposed systems.
Hunt for indicators of compromise tied to this vulnerability and confirm logging/EDR coverage on affected assets.
Authoritative references
Remediate CVE-2020-3118 — and stay ahead of the next one
CVE-2020-3118 is listed in the CISA KEV catalog as actively exploited — treat remediation as urgent. Scan your domain free to see whether CVE-2020-3118 and other Cisco issues affect you and get a prioritized remediation report (full report from ₹999) — or stream the full feed of 1,600+ actively-exploited CVEs straight into your SOC.
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