CVE-2023-38710 — An issue was discovered in Libreswan before 4

An issue was discovered in Libreswan before 4.12. When an IKEv2 Child SA REKEY packet contains an invalid IPsec protocol ID number of 0 or 1, an error notify INVALID_SPI is sent back. The notify payload's protocol ID is copied from the incoming packet, but the code that veri

01What is this vulnerability?

An issue was discovered in Libreswan before 4.12. When an IKEv2 Child SA REKEY packet contains an invalid IPsec protocol ID number of 0 or 1, an error notify INVALID_SPI is sent back. The notify payload's protocol ID is copied from the incoming packet, but the code that verifies outgoing packets fails an assertion that the protocol ID must be ESP (2) or AH(3) and causes the pluto daemon to crash…

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-08-25T00:00:00.000Z
• Last modified: 2024-11-26T21:53:27.752Z

09References

• github.com — https://github.com/libreswan/libreswan/tags
• libreswan.org — https://libreswan.org/security/CVE-2023-38710/