CVE catalog
CVE-2021-30639
tomcat9: CVE-2021-30639
- Severity
- High · CVSS 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 6.89% · Oct 25, 2026
A vulnerability in Apache Tomcat allows an attacker to remotely trigger a denial of service. An error introduced as part of a change to improve error handling during non-blocking I/O meant that the error flag associated with the Request object was not reset between requests. This meant that once a non-blocking I/O error occurred, all future requests handled by that request object would fail. Users were able to trigger non-blocking I/O errors, e.g. by dropping a connection, thereby creating the possibility of triggering a DoS. Applications that do not use non-blocking I/O are not exposed to this vulnerability. This issue affects Apache Tomcat 10.0.3 to 10.0.4; 9.0.44; 8.5.64.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | tomcat9 | sid | 9.0.122-1 | not affected |
| Debian | tomcat9 | forky | 9.0.122-1 | not affected |
| Debian | tomcat9 | trixie | 9.0.95-1 | not affected |
| Debian | tomcat9 | bookworm | 9.0.70-2 | not affected |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | tomcat9 | source | sid | Not affected | unimportant | Not reported | Not reported |
| Debian | tomcat9 | source | forky | Not affected | unimportant | Not reported | Not reported |
| Debian | tomcat9 | source | trixie | Not affected | unimportant | Not reported | Not reported |
| Debian | tomcat9 | source | bookworm | Not affected | unimportant | Not reported | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [libtomcat9-java]Not affected
Source package: [tomcat9]
Details (2)
9.0.70-2· all · bookwormNot affected
dsa · tomcat9 · debian · bookworm
9.0.70-2· all · bookwormNot affected
dsa · tomcat9 · debian · bookworm
Observed:
References
- [https://osv.dev/vulnerability/UBUNTU-CVE-2021-30639]
- [https://security-tracker.debian.org/tracker/CVE-2021-30639]
- [https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-30639.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2021/wid-sec-w-2022-1116.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]