PatchTheCVECVE-2009-1574: racoon/isakmp_frag.c in ipsec-tools before 0.7.2 allows remote attackers to cause a denial of service (crash)
CVE-2009-1574 is a medium-severity flaw (CVSS 5.0) affecting ipsec-tools. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
racoon/isakmp_frag.c in ipsec-tools before 0.7.2 allows remote attackers to cause a denial of service (crash) via crafted fragmented packets without a payload, which triggers a NULL pointer dereference.
Why this priority
- EPSS top 4%: very likely to be exploited
- Public exploit reference
A fixed release or distro patch exists.
Risk facts
| CVSS score | 5.0 (Medium) |
| EPSS exploit chance | 11.6% (top 4%) |
| CISA exploited list | No |
| Published | 2009-05-06 |
| Last modified | 2026-06-16 |
Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Public exploits and detection
Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.
- Exploit-DB: IPsec-Tools < 0.7.2 (racoon frag-isakmp) - Multiple Remote Denial of Service Vulnerabilities (PoC)
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2009-1574?
ipsec-tools: upgrade to newer than 0.7.1. Exact commands for each OS are on this page.
Is CVE-2009-1574 being exploited?
CVE-2009-1574 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2009-1574 affect?
CVE-2009-1574 affects ipsec-tools. Severity is medium (CVSS 5.0). racoon/isakmp_frag.c in ipsec-tools before 0.7.2 allows remote attackers to cause a denial of service (crash) via crafted fragmented packets without a payload, which triggers a NULL pointer dereference.
How urgent is CVE-2009-1574?
Priority 47/100. EPSS top 4%: very likely to be exploited; Public exploit reference
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