CVE-2023-34319

Published: 9 August 2023

The fix for XSA-423 added logic to Linux'es netback driver to deal with a frontend splitting a packet in a way such that not all of the headers would come in one piece. Unfortunately the logic introduced there didn't account for the extreme case of the entire packet being split into as many pieces as permitted by the protocol, yet still being smaller than the area that's specially dealt with to keep all (possible) headers together. Such an unusual packet would therefore trigger a buffer overrun in the driver.

From the Ubuntu Security Team

Ross Lagerwall discovered that the Xen netback backend driver in the Linux kernel did not properly handle certain unusual packets from a paravirtualized network frontend, leading to a buffer overflow. An attacker in a guest VM could use this to cause a denial of service (host system crash) or possibly execute arbitrary code.

Status

Severity score breakdown

References

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-34319
• https://git.kernel.org/linus/534fc31d09b706a16d83533e16b5dc855caf7576
• https://marc.info/?l=oss-security&m=169151395214375&w=2
• https://xenbits.xen.org/xsa/advisory-432.html
• https://ubuntu.com/security/notices/USN-6343-1
• NVD
• Launchpad
• Debian

Bugs

• https://bugzilla.redhat.com/show_bug.cgi?id=2230156
• https://bugzilla.suse.com/show_bug.cgi?id=1213546