CVE-2021-43980
Description
The simplified implementation of blocking reads and writes introduced in Tomcat 10 and back-ported to Tomcat 9.0.47 onwards exposed a long standing (but extremely hard to trigger) concurrency bug in Apache Tomcat 10.1.0 to 10.1.0-M12, 10.0.0-M1 to 10.0.18, 9.0.0-M1 to 9.0.60 and 8.5.0 to 8.5.77 that could cause client connections to share an Http11Processor instance resulting in responses, or part responses, to be received by the wrong client.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 9.0.62-1 |
| sid | Fixed | 9.0.62-1 |
| forky | Fixed | 9.0.62-1 |
| bullseye | Fixed | 9.0.43-2~deb11u4 |
| bookworm | Fixed | 9.0.62-1 |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| Maven | org.apache.tomcat:tomcat | >=8.5.0,<8.5.78 | 8.5.78 |
| Maven | org.apache.tomcat:tomcat | >=9.0.0-M1,<9.0.62 | 9.0.62 |
| Maven | org.apache.tomcat:tomcat | >=10.0.0-M1,<10.0.20 | 10.0.20 |
| Maven | org.apache.tomcat:tomcat | >=10.1.0-M1,<10.1.0-M14 | 10.1.0-M14 |
References
- https://www.suse.com/security/cve/CVE-2021-43980.html
- https://nvd.nist.gov/vuln/detail/CVE-2021-43980
- https://github.com/apache/tomcat/commit/170e0f792bd18ff031677890ba2fe50eb7a376c1
- https://github.com/apache/tomcat/commit/17f177eeb7df5938f67ef9ea580411b120195f13
- https://github.com/apache/tomcat/commit/4a00b0c0890538b9d3107eef8f2e0afadd119beb
- https://github.com/apache/tomcat/commit/9651b83a1d04583791525e5f0c4c9089f678d9fc
- https://github.com/apache/tomcat
- https://lists.apache.org/thread/3jjqbsp6j88b198x5rmg99b1qr8ht3g3
- https://lists.debian.org/debian-lts-announce/2022/10/msg00029.html
- https://tomcat.apache.org/security-10.html
- https://tomcat.apache.org/security-8.html
- https://tomcat.apache.org/security-9.html
- https://www.debian.org/security/2022/dsa-5265
- http://www.openwall.com/lists/oss-security/2022/09/28/1
- https://security-tracker.debian.org/tracker/CVE-2021-43980
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.