Vulnerability Description
In pf packet processing with a 'scrub fragment reassemble' rule, a packet containing multiple IPv6 fragment headers would be reassembled, and then immediately processed. That is, a packet with multiple fragment extension headers would not be recognized as the correct ultimate payload. Instead a packet with multiple IPv6 fragment headers would unexpectedly be interpreted as a fragmented packet, rather than as whatever the real payload is. As a result, IPv6 fragments may bypass pf firewall rules written on the assumption all fragments have been reassembled and, as a result, be forwarded or processed by the host.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Freebsd | Freebsd | < 12.4 |
Related Weaknesses (CWE)
References
- http://www.openwall.com/lists/oss-security/2023/09/08/5Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2023/09/08/6Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2023/09/08/7Mailing ListThird Party Advisory
- https://security.FreeBSD.org/advisories/FreeBSD-SA-23:10.pf.ascVendor Advisory
- https://security.netapp.com/advisory/ntap-20231221-0009/
- http://www.openwall.com/lists/oss-security/2023/09/08/5Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2023/09/08/6Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2023/09/08/7Mailing ListThird Party Advisory
- https://security.FreeBSD.org/advisories/FreeBSD-SA-23:10.pf.ascVendor Advisory
- https://security.netapp.com/advisory/ntap-20231221-0009/
FAQ
What is CVE-2023-4809?
CVE-2023-4809 is a vulnerability with a CVSS score of 7.5 (HIGH). In pf packet processing with a 'scrub fragment reassemble' rule, a packet containing multiple IPv6 fragment headers would be reassembled, and then immediately processed. That is, a packet with multip...
How severe is CVE-2023-4809?
CVE-2023-4809 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2023-4809?
Check the references section above for vendor advisories and patch information. Affected products include: Freebsd Freebsd.