BSD Portserlang -- SSH plaintext recovery attack against CBC ciphers
The Erlang/OTP team reports: The SSH client and server now reject incoming packets not aligned to the cipher block size as required by RFC 4253 section 6. For CBC ciphers, a timing-safe "packet discard" mechanism (CVE-2008-5161 mitigation) ensures structural errors are indistinguishable from MAC failures before disconnecting. AEAD and encrypt-then-MAC modes disconnect immediately.
Affected versions
- erlang < 28.5.0.5,4
- erlang-runtime27 < 27.3.4.16
- erlang-runtime28 < 28.5.0.5
- erlang-runtime29 < 29.0.5
By system
3 still vulnerable, 4 fixed. Where VuXML applies (FreeBSD, DragonFly, FreeBSD's derivatives) a port is vulnerable while its version is in a range; pkgsrc says itself whether it lists a CVE of this advisory; OpenBSD and MidnightBSD keep no list this site reads, so their row is only an estimate: FreeBSD's ranges applied to upstream's version.
| System | Port | Version | State | Fixed |
|---|---|---|---|---|
| DragonFly | lang/erlang | 25.3.2.7_1,4 | vulnerable since 2026-08-04 | |
| NetBSD | lang/erlang | 27.3.4.7 | not listed | |
| MidnightBSD | lang/erlang | 25.3.2.20_1,4 | in range, by version | |
| FreeBSD | lang/erlang | 28.5.0.8_1,4 | fixed | (2 days after) |
| DragonFly | lang/erlang-runtime27 | 27.3.4 | vulnerable since 2026-08-04 | |
| FreeBSD | lang/erlang-runtime27 | 27.3.4.19_1 | fixed | (2 days after) |
| DragonFly | lang/erlang-runtime28 | 28.0 | vulnerable since 2026-08-04 | |
| MidnightBSD | lang/erlang-runtime28 | 28.5.0.8 | out of range, by version | |
| FreeBSD | lang/erlang-runtime28 | 28.5.0.8_1 | fixed | (2 days after) |
| FreeBSD | lang/erlang-runtime29 | 29.1.2_1 | fixed | (2 days after) |