CyberSecBulletin
CVE-2022-42309NVD status: Modified

xen: Release of Invalid Pointer or Reference

Published Updated By the CyberSecBulletin desk

CVE-2022-42309 is a high-severity release of invalid pointer or reference vulnerability in xen, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.3% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of xen you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on xenbits.xen.org for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
XenxenNot specified in the recordNot stated
DebianDebian Linux11.0Not stated
Fedora ProjectFedora35; 36; 37Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H. Scored by NVD.

Official description

Xenstore: Guests can crash xenstored Due to a bug in the fix of XSA-115 a malicious guest can cause xenstored to use a wrong pointer during node creation in an error path, resulting in a crash of xenstored or a memory corruption in xenstored causing further damage. Entering the error path can be controlled by the guest e.g. by exceeding the quota value of maximum nodes per domain.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Release of Invalid Pointer or Reference

The product attempts to return a memory resource to the system, but it calls the wrong release function or calls the appropriate release function incorrectly.

How developers prevent this class of flaw

  • Only call matching memory management functions. Do not mix and match routines. For example, when you allocate a buffer with malloc(), dispose of the original pointer with free().
  • When programming in C++, consider using smart pointers provided by the boost library to help correctly and consistently manage memory.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, glibc in Linux provides protection against free of invalid pointers.

More Release of Invalid Pointer or Reference vulnerabilities (CWE-763)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in xen

All xen vulnerabilities

Recent Release of Invalid Pointer or Reference vulnerabilities

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