Description
smtpd/lka_filter.c in OpenSMTPD before 6.8.0p1, in certain configurations, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted pattern of client activity, because the filter state machine does not properly maintain the I/O channel between the SMTP engine and the filters layer.
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 | opensmtpd | 6.8.0p2-1 | — |
| Debian 13 | opensmtpd | 6.8.0p2-1 | — |
| Debian 12 | opensmtpd | 6.8.0p2-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | opensmtpd | No fix yet | — |
| Ubuntu 26.04 LTS | opensmtpd | No fix yet | — |
| Ubuntu 25.10 | opensmtpd | No fix yet | — |
| Ubuntu 24.04 LTS | opensmtpd | No fix yet | — |
| Ubuntu 22.04 LTS | opensmtpd | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | opensmtpd | No fix yet | — |
| Ubuntu Pro 14.04 LTS | opensmtpd | No fix yet | — |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.13 | opensmtpd | 6.7.1p1-r1 | — |
| Alpine v3.12 | opensmtpd | 6.6.4p1-r2 | — |
| Alpine v3.11 | opensmtpd | 6.6.4p1-r1 | — |
References
- https://poolp.org/posts/2020-12-24/december-2020-opensmtpd-6.8.0p1-released-fixed-several-bugs-proposed-several-diffs-book-is-on-github/
- https://www.mail-archive.com/misc%40opensmtpd.org/msg05188.html
- https://github.com/openbsd/src/commit/6c3220444ed06b5796dedfd53a0f4becd903c0d1
- FEDORA-2021-71fbdecdf8 vendor-advisory
- FEDORA-2021-848fd34b0b vendor-advisory
- GLSA-202105-12 vendor-advisory