CVE-2021-3782
Published: 30 August 2022
An internal reference count is held on the buffer pool, incremented every time a new buffer is created from the pool. The reference count is maintained as an int; on LP64 systems this can cause the reference count to overflow if the client creates a large number of wl_shm buffer objects, or if it can coerce the server to create a large number of external references to the buffer storage. With the reference count overflowing, a use-after-free can be constructed on the wl_shm_pool tracking structure, where values may be incremented or decremented; it may also be possible to construct a limited oracle to leak 4 bytes of server-side memory to the attacking client at a time.
Priority
Status
| Package | Release | Status |
|---|---|---|
|
wayland Launchpad, Ubuntu, Debian |
bionic |
Released
(1.16.0-1ubuntu1.1~18.04.4)
|
| focal |
Released
(1.18.0-1ubuntu0.1)
|
|
| jammy |
Released
(1.20.0-1ubuntu0.1)
|
|
| kinetic |
Not vulnerable
(1.21.0-1)
|
|
| trusty |
Ignored
(out of standard support)
|
|
| upstream |
Needs triage
|
|
| xenial |
Released
(1.12.0-1~ubuntu16.04.3+esm1)
|
|
|
Patches: upstream: https://gitlab.freedesktop.org/wayland/wayland/-/commit/b19488c7154b902354cb26a27f11415d7799b0b2 |
||
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 9.8 |
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | High |
| Availability impact | High |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |