CVE-2021-20235 Information

Description

There’s a flaw in the zeromq server in versions before 4.3.3 in src/decoder_allocators.hpp. The decoder static allocator could have its sized changed but the buffer would remain the same as it is a static buffer. A remote unauthenticated attacker who sends a crafted request to the zeromq server could trigger a buffer overflow WRITE of arbitrary data if CURVE/ZAP authentication is not enabled. The greatest impact of this flaw is to application availability data integrity and confidentiality.

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Reference

https://bugzilla.redhat.com/show_bug.cgi?id=1921983 https://github.com/zeromq/libzmq/security/advisories/GHSA-fc3w-qxf5-7hp6

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

8.1