CVE-2021-20236 is a critical stack buffer overflow vulnerability affecting ZeroMQ server versions prior to 4.3.3, including those in Fedora Project and Red Hat products. A remote, unauthenticated attacker can trigger this flaw by sending specially crafted subscription and unsubscription requests, leading to complete compromise of confidentiality, integrity, and availability. Despite its critical severity (CVSS 9.8), there is currently no public exploit code, Metasploit modules, or evidence of active exploitation, and it has received minimal community discussion or media coverage.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
< 4.3.3CPE matchmatch criteria | cpe:2.3:a:zeromq:zeromq:*:*:*:*:*:*:*:* | ||
2.0CPE matchmatch criteria | cpe:2.3:a:redhat:ceph_storage:2.0:*:*:*:*:*:*:* | ||
7.0CPE matchmatch criteria | cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* | ||
33CPE matchmatch criteria | cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.
A flaw was found in the ZeroMQ server in versions before 4.3.3. This flaw allows a malicious client to cause a stack buffer overflow on the server by sending crafted topic subscription requests and then unsubscribing. The highest threat from this vulnerability is to confidentiality integrity as well as system availability.
May 11, 2021zeromq: Stack overflow on server running PUB/XPUB socket
Sep 7, 2020