CVE-2021-43850 json
Denial of Service in discourse
published 2022-01-04 4 y ago modified 2026-09-08 2 mo ago also BIT-discourse-2021-43850 , EUVD-2021-30719 , GHSA-59jr-pj65-qmvr
- cvss
- 6.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.9%
- EPSS 0.9% chance of exploitation in 30 days, percentile 58%
- public exploits
- 0
- none known
Summary
Discourse is an open source platform for community discussion. In affected versions admins users can trigger a Denial of Service attack via the `/message-bus/_diagnostics` path. The impact of this vulnerability is greater on multisite Discourse instances (where multiple forums are served from a single application server) where any admin user on any of the forums are able to visit the `/message-bus/_diagnostics` path. The problem has been patched. Please upgrade to 2.8.0.beta10 or 2.7.12. No workarounds for this issue exist.
Patch / fix
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 18 mo ago
Exploit prediction
0.85% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/discourse/discourse/security/advisories/GHSA-59jr-pj65-qmvr referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:N/A:H |
| NVD | 3.1 | 6.8 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H |
| NVD | 2.0 | 4.0 | AV:N/AC:L/Au:S/C:N/I:N/A:P |
| OSV | 3.1 | 6.8 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| bitnami | discourse | <2.7.12 |
2.7.12 |
Affected products
- discourse discourse
Classification
- Weakness
-
- CWE-20 Improper Input Validation
References
-
github.com
/discourse/discourse/commit/7a8ec129fb54f188b2da6588c9d24d3a36eb0d39
patch, third-party-advisory, advisory
-
github.com
/discourse/discourse/security/advisories/GHSA-59jr-pj65-qmvr
exploit, third-party-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-43850
web
Sources
- CVE List CVE-2021-43850
- NVD CVE-2021-43850
- OSV BIT-discourse-2021-43850
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