CVE-2021-20235

Publication date 1 April 2021

Last updated 24 July 2024

Ubuntu priority

Cvss 3 Severity Score

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.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
zeromq3	24.04 LTS noble	Not affected
	23.10 mantic	Not affected
	23.04 lunar	Not affected
	22.10 kinetic	Not affected
	22.04 LTS jammy	Not affected
	21.10 impish	Not affected
	21.04 hirsute	Not affected
	20.10 groovy	Ignored
	20.04 LTS focal	Fixed 4.3.2-2ubuntu1.20.04.1~esm2 Ubuntu Pro
	18.04 LTS bionic	Fixed 4.2.5-1ubuntu0.2+esm2 Ubuntu Pro
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected

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Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
zeromq3	Upstream: https://github.com/zeromq/libzmq/pull/3902

Severity score breakdown

Parameter	Value
Base score	8.1 · High
Attack vector	Network
Attack complexity	High
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	High
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

USN-4920-1
ZeroMQ vulnerabilities
15 June 2022