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No exploitation reportedFix available

CVE-2021-32921

No exploitation reported by the sources we read.

  • Published2021-05-13
  • Fixed in0.11.9
  • WeaknessCWE-362

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

An issue was discovered in Prosody before 0.11.9. It does not use a constant-time algorithm for comparing certain secret strings when running under Lua 5.2 or later. This can potentially be used in a timing attack to reveal the contents of secret strings to an attacker.

Timeline

dates in UTC
  1. 2021-05-1316:15CVE publishedNVD

Versions per branch

NVD
Prosodyversion to verify
BranchAffectedFixed in
0.11< 0.11.90.11.9
Fedoraproject fedora
BranchAffectedFixed in
32.x= 32no fix published
33.x= 33no fix published
34.x= 34no fix published
Debian debian linux
BranchAffectedFixed in
9.0= 9.0no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • prosodyUbuntu:Pro:18.04:LTSall versions · no fixed version listed
  • prosodyUbuntu:22.04:LTSall versions · no fixed version listed
  • prosodyUbuntu:20.04:LTSall versions · no fixed version listed
  • prosodyUbuntu:16.04:LTSall versions · no fixed version listed
  • prosodyDebian:14all versions · fixed in 0.11.9-1
  • prosodyDebian:13all versions · fixed in 0.11.9-1
  • prosodyDebian:12all versions · fixed in 0.11.9-1
  • prosodyDebian:10all versions · fixed in 0.11.2-1+deb10u1

15 more package ranges on OSV.dev

Full record on NVD

Fix

  1. Update Prosody to 0.11.9

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

  • EUVD-2021-19643same flawENISA EUVD · LicenseRef-ENISA-legal-notice
  • GHSA-vh63-h6gp-hw6wsame flawGitHub Advisory Database · CC-BY-4.0
  • DLA-2687-1advisory covering several CVEsDebian · LicenseRef-unstated
  • DSA-4916-1advisory covering several CVEsDebian · LicenseRef-unstated

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Published
2021-05-13
Last Modified
2026-06-17
NVD status
Modified
GitHub Advisory
GHSA-vh63-h6gp-hw6w

Frequently asked questions

What is CVE-2021-32921?

An issue was discovered in Prosody before 0.11.9. It does not use a constant-time algorithm for comparing certain secret strings when running under Lua 5.2 or later. This can potentially be used in a timing attack to reveal the contents of secret strings to an attacker.

Is CVE-2021-32921 actively exploited?

Active exploitation of CVE-2021-32921 has not been confirmed. Its EPSS score was 1.6% on 2026-11-08, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-32921?

CVE-2021-32921 has a CVSS v3 base score of 5.9 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.

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Sources for this record