cbcvebase.
CVE-2021-20236
published 2021-05-28

CVE-2021-20236: 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…

PriorityP354critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
1.60%
73.1th percentile
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.

Affected

7 ranges
VendorProductVersion rangeFixed in
debianzeromq3< zeromq3 4.3.3-1 (bookworm)zeromq3 4.3.3-1 (bookworm)
fedoraprojectfedora
msrccm1_zeromq_4.3.4-1_on_cbl_mariner_1.0
redhatceph_storage
redhatenterprise_linux
zeromqzeromq< 4.3.34.3.3
zeromqzeromq

CVSS provenance

nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv2.07.5HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P
osv9.8CRITICAL
vendor_debian9.8CRITICAL
vendor_msrc9.8CRITICAL
vendor_redhat9.8CRITICAL
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.