crossbeam-channel Vulnerable to Double Free on Drop

Description

The internal Channel type's Drop method has a race
which could, in some circumstances, lead to a double-free.
This could result in memory corruption.

Quoting from the
upstream description in merge request #1187:

> The problem lies in the fact that dicard_all_messages contained two paths that could lead to head.block being read but only one of them would swap the value. This meant that dicard_all_messages could end up observing a non-null block pointer (and therefore attempting to free it) without setting head.block to null. This would then lead to Channel::drop making a second attempt at dropping the same pointer.

The bug was introduced while fixing a memory leak, in
upstream MR #1084,
first published in 0.5.12.

The fix is in
upstream MR #1187
and has been published in 0.5.15

Basic information

Type
reviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Source code
Browse source ↗
Published (advisory)
2025-04-10 14:30:39 UTC
Updated
2025-09-25 21:13:02 UTC
GitHub reviewed
2025-04-10 14:30:39 UTC

EPSS Score

Score Percentile
0.48% 64.88%

CVSS Scores

Base score Version Severity Vector
6.3 4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:P)
Additional preconditions must be present for exploitation.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:L)
Limited integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:L)
Limited availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.

Identifiers

CWEs

CWE id Name
CWE-415 Double Free

Credits

  • hoerup (analyst)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
rust crossbeam-channel >= 0.5.12, < 0.5.15 0.5.15

References

cvelogic Threat Intelligence