CVE-2023-34323: xen Null Dereference — Fix

Description

When a transaction is committed, C Xenstored will first check the quota is correct before attempting to commit any nodes. It would be possible that accounting is temporarily negative if a node has been removed outside of the transaction. Unfortunately, some versions of C Xenstored are assuming that the quota cannot be negative and are using assert() to confirm it. This will lead to C Xenstored crash when tools are built without -DNDEBUG (this is the default).

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CVSS v3.1 Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-476 CWE-476

Affected Products

Vendor	Product	Versions
xen	xen	< 4.17.0

References

Advisories & Patches

https://xenbits.xenproject.org/xsa/advisory-440.html https://xenbits.xenproject.org/xsa/advisory-440.html

Other References

http://xenbits.xen.org/xsa/advisory-440.html

Frequently Asked Questions

What is CVE-2023-34323? +

When a transaction is committed, C Xenstored will first check the quota is correct before attempting to commit any nodes. It would be possible that accounting is temporarily negative if a node has been removed outside of the transaction. Unfortunately, some versions of C Xenstored are assuming that the quota cannot be negative and are using assert() to confirm it. This will lead to C Xenstored crash when tools are built without -DNDEBUG (this is the default). It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2023-34323? +

CVE-2023-34323 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2023-34323? +

CVE-2023-34323 affects products from xen, specifically: xen. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2023-34323? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2023-34323