Memory corruption via buffer-pool reference-count overflow
Published Sep 23, 2022 · Updated May 22, 2025
Integer overflow in Wayland libwayland-server before 1.20.91 allows local users to corrupt compositor memory through shared-memory objects. On LP64 systems, wl_shm_pool keeps its internal reference count in an int and increments it for every buffer or external storage reference until it wraps. A client with access to the compositor's UNIX-domain socket can then construct a use-after-free that modifies tracking values or leaks four bytes of server memory per oracle query.
Summary
What happened
Integer overflow in Wayland libwayland-server before 1.20.91 allows local users to corrupt compositor memory through shared-memory objects. On LP64 systems, wl_shm_pool keeps its internal reference count in an int and increments it for every buffer or external storage reference until it wraps. A client with access to the compositor's UNIX-domain socket can then construct a use-after-free that modifies tracking values or leaks four bytes of server memory per oracle query.
The record
- CVE
- CVE-2021-3782
- Published
- Sep 23, 2022
- Updated
- May 22, 2025
- Vendor
- Wayland
- Product
- Wayland
- Classifications
- CWE-190
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 23, 2022CVE publishedPublication date reported by the CVE source.
- May 22, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=wayland 1.20.91
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
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Wayland issue 224proof of concept · unverified
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo