| Name | CVE-2020-14145 |
| Description | The client side in OpenSSH 5.7 through 8.4 has an Observable Discrepancy leading to an information leak in the algorithm negotiation. This allows man-in-the-middle attackers to target initial connection attempts (where no host key for the server has been cached by the client). NOTE: some reports state that 8.5 and 8.6 are also affected. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| openssh (PTS) | jessie, jessie (lts) | 1:6.7p1-5+deb8u10 | vulnerable |
| stretch (security) | 1:7.4p1-10+deb9u6 | vulnerable |
| stretch (lts), stretch | 1:7.4p1-10+deb9u9 | vulnerable |
| buster | 1:7.9p1-10+deb10u2 | vulnerable |
| buster (security) | 1:7.9p1-10+deb10u4 | vulnerable |
| bullseye (security), bullseye | 1:8.4p1-5+deb11u3 | vulnerable |
| bookworm (security), bookworm | 1:9.2p1-2+deb12u2 | vulnerable |
| trixie | 1:9.6p1-4 | vulnerable |
| sid | 1:9.7p1-4 | vulnerable |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| openssh | source | (unstable) | (unfixed) | unimportant | | |
Notes
https://www.fzi.de/en/news/news/detail-en/artikel/fsa-2020-2-ausnutzung-eines-informationslecks-fuer-gezielte-mitm-angriffe-auf-ssh-clients/
https://www.fzi.de/fileadmin/user_upload/2020-06-26-FSA-2020-2.pdf
The OpenSSH project is not planning to change the behaviour of OpenSSH regarding
the issue, details in "3.1 OpenSSH" in the publication.
Partial mitigation: https://anongit.mindrot.org/openssh.git/commit/?id=b3855ff053f5078ec3d3c653cdaedefaa5fc362d (V_8_4_P1)