CVE-2018-0155
Published: March 3, 2022
Official Description
A vulnerability in the Bidirectional Forwarding Detection (BFD) offload implementation of Cisco Catalyst 4500 Series Switches and Cisco Catalyst 4500-X Series Switches could allow an unauthenticated, remote attacker to cause a crash of the iosd process, causing a denial-of-service (DoS) condition.
CISA KEV Advisory
Cisco Catalyst Bidirectional Forwarding Detection Denial-of-Service Vulnerability
A vulnerability in the Bidirectional Forwarding Detection (BFD) offload implementation of Cisco Catalyst 4500 Series Switches and Cisco Catalyst 4500-X Series Switches could allow an unauthenticated, remote attacker to cause a crash of the iosd process, causing a denial-of-service (DoS) condition.
Apply updates per vendor instructions.
Risk Analysis
This vulnerability in Cisco Catalyst 4500 Series Switches and 4500-X Series Switches' BFD offload implementation could allow an unauthenticated, remote attacker to crash the iosd process, resulting in a denial-of-service condition. This high-severity flaw can disrupt network operations. The high severity and confirmed exploitation in the wild make this an urgent concern.
This vulnerability has been actively exploited in the wild and is included in CISA's KEV catalog, confirming its active use by threat actors. This indicates a high probability of successful exploitation by unauthenticated remote attackers.
Apply the latest security updates for Cisco Catalyst 4500 Series Switches and Cisco Catalyst 4500-X Series Switches to mitigate this denial-of-service vulnerability. Review and harden BFD configurations.
Technical Analysis
CVE-2018-0155 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2018-0155 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
All References (1)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2018-0155 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1