Root code execution via hierarchy-event heap overflow
Published Feb 28, 2024 · Updated Nov 6, 2025
Heap buffer overflow in X.Org X Server before 21.1.11 and Xwayland before 23.2.4 allows local users to execute code as root. XISendDeviceHierarchyEvent allocates 256 xXIHierarchyInfo entries but can append two for every reused device ID, writing past the heap allocation. Access to an X server connection is required; exploitation can crash the server or run code with its privileges, including root on privileged installations.
Summary
What happened
Heap buffer overflow in X.Org X Server before 21.1.11 and Xwayland before 23.2.4 allows local users to execute code as root. XISendDeviceHierarchyEvent allocates 256 xXIHierarchyInfo entries but can append two for every reused device ID, writing past the heap allocation. Access to an X server connection is required; exploitation can crash the server or run code with its privileges, including root on privileged installations.
The record
- CVE
- CVE-2024-21885
- Published
- Feb 28, 2024
- Updated
- Nov 6, 2025
- Vendor
- Red Hat
- Product
- Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
- Classifications
- CWE-122, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 28, 2024CVE publishedPublication date reported by the CVE source.
- Nov 6, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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