| Name | CVE-2021-20235 |
| 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. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DLA-2588-1, ELA-1184-1 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| zeromq3 (PTS) | jessie, jessie (lts) | 4.0.5+dfsg-2+deb8u4 | fixed |
| stretch (security), stretch (lts), stretch | 4.2.1-4+deb9u4 | fixed | |
| buster, buster (lts) | 4.3.1-4+deb10u3 | fixed | |
| buster (security) | 4.3.1-4+deb10u2 | vulnerable | |
| bullseye | 4.3.4-1+deb11u1 | fixed | |
| bookworm | 4.3.4-6 | fixed | |
| sid, trixie | 4.3.5-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| zeromq3 | source | jessie | (not affected) | |||
| zeromq3 | source | stretch | 4.2.1-4+deb9u4 | DLA-2588-1 | ||
| zeromq3 | source | buster | 4.3.1-4+deb10u3 | ELA-1184-1 | ||
| zeromq3 | source | (unstable) | 4.3.3-1 |
[buster] - zeromq3 <no-dsa> (Minor issue)
https://github.com/zeromq/libzmq/pull/3902
https://github.com/zeromq/libzmq/security/advisories/GHSA-fc3w-qxf5-7hp6
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=21984
[jessie] - zeromq3 <not-affected> (Vulnerable code introduced later)