Description
fetchmail 5.9.9 through 6.3.19 does not properly limit the wait time after issuing a (1) STARTTLS or (2) STLS request, which allows remote servers to cause a denial of service (application hang) by acknowledging the request but not sending additional packets.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | fetchmail | 6.3.22-1 | — |
| Debian 13 | fetchmail | 6.3.22-1 | — |
| Debian 12 | fetchmail | 6.3.22-1 | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | fetchmail | 6.3.26-13.4 | openSUSE-SU-2024:10194-1 |
Advisories 1
- openSUSE-SU-2024:10194-1 fetchmail-6.3.26-13.4 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- [oss-security] 20110531 Re: CVE request for fetchmail STARTTLS hang (Denial of Service) mailing-list
- 48043 vdb-entry
- FEDORA-2011-8011 vendor-advisory
- [oss-security] 20110531 Re: CVE request for fetchmail STARTTLS hang (Denial of Service) mailing-list
- [oss-security] 20110530 CVE request for fetchmail STARTTLS hang (Denial of Service) mailing-list
- 20110606 fetchmail security announcement fetchmail-SA-2011-01 (CVE-2011-1947) mailing-list
- FEDORA-2011-8059 vendor-advisory
- http://gitorious.org/fetchmail/fetchmail/blobs/legacy_63/fetchmail-SA-2011-01.txt
- 1025605 vdb-entry
- MDVSA-2011:107 vendor-advisory
- FEDORA-2011-8021 vendor-advisory
- http://www.fetchmail.info/fetchmail-SA-2011-01.txt
- [oss-security] 20110601 Re: CVE request for fetchmail STARTTLS hang (Denial of Service) mailing-list
- fetchmail-starttls-dos(67700) vdb-entry