Known exploited · IETF
CVE-2023-29552: Service Location Protocol (SLP) Denial-of-Service Vulnerability
What it is
The Service Location Protocol (SLP) contains a denial-of-service (DoS) vulnerability that could allow an unauthenticated, remote attacker to register services and use spoofed UDP traffic to conduct a denial-of-service (DoS) attack with a significant amplification factor.
- Vendor
- IETF
- Product
- Service Location Protocol (SLP)
- Added to KEV
- November 8, 2023
- CISA due date
- November 29, 2023
- Ransomware use
- Unknown
- Weakness
- Not mapped by CISA
What CISA requires
Apply mitigations per vendor instructions or disable SLP service or port 427/UDP on all systems running on untrusted networks, including those directly connected to the Internet.
Forensic triage
No
What to do now
- Find every instance of Service Location Protocol (SLP) you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before November 29, 2023 if you are bound by CISA's deadline, sooner if it faces the internet.
- Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
References
H2 Security
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Start freeSource: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.