Reported

December 9, 2018

Issued

October 1, 2020 (last modified: June 13, 2023)

Package

crossbeam (crates.io)

Type

Vulnerability

Keywords

#concurrency #memory-management #memory-corruption

Aliases

• CVE-2018-20996
• GHSA-c3cw-c387-pj65

References

• https://github.com/crossbeam-rs/crossbeam-epoch/issues/82

CVSS Score

9.8 CRITICAL

CVSS Details

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

CVSS Vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Patched

• >=0.4.1

Unaffected

• <0.4.0

Description

Even if an element is popped from a queue, crossbeam would run its destructor inside the epoch-based garbage collector. This is a source of double frees.

The flaw was corrected by wrapping elements inside queues in a ManuallyDrop.

Thanks to @c0gent for reporting the issue.

Advisory available under CC0-1.0 license.