X server: Improper Resource Locking
CVE-2022-49737 is a high-severity improper resource locking vulnerability in X server from X.Org, with a CVSS 3.1 base score of 7.7 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected X server versions: 20.11 through 21.1.16. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.34% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of X server you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
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
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- 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
- LowSome restricted data can be read.
- Integrity
- LowLimited modification of data is possible.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:H. Scored by CNA (mitre.org).
Official description
In X.Org X server 20.11 through 21.1.16, when a client application uses easystroke for mouse gestures, the main thread modifies various data structures used by the input thread without acquiring a lock, aka a race condition. In particular, AttachDevice in dix/devices.c does not acquire an input lock.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Resource Locking
The product must have exclusive access to a resource, but it does not lock or does not correctly lock that resource.
How developers prevent this class of flaw
- Use synchronization when locking a resource.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Other vulnerabilities in X server
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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