CVE-2023-34319

Linux: buffer overrun in netback due to unusual packet

Description

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.

Remediation

Workaround:

  • Using another PV network backend (e.g. the qemu based "qnic" backend) will mitigate the problem. Using a dedicated network driver domain per guest will mitigate the problem.

Category

7.8
CVSS
Severity: High
CVSS 3.1 •
EPSS 0.02%
Vendor Advisory xenproject.org
Affected: Linux Linux
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2023-34319?
CVE-2023-34319 has been scored as a high severity vulnerability.
How to fix CVE-2023-34319?
As a workaround for remediating CVE-2023-34319: Using another PV network backend (e.g. the qemu based "qnic" backend) will mitigate the problem. Using a dedicated network driver domain per guest will mitigate the problem.
Is CVE-2023-34319 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2023-34319 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-34319?
CVE-2023-34319 affects Linux Linux.
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