| Name | CVE-2015-5600 |
| Description | The kbdint_next_device function in auth2-chall.c in sshd in OpenSSH through 6.9 does not properly restrict the processing of keyboard-interactive devices within a single connection, which makes it easier for remote attackers to conduct brute-force attacks or cause a denial of service (CPU consumption) via a long and duplicative list in the ssh -oKbdInteractiveDevices option, as demonstrated by a modified client that provides a different password for each pam element on this list. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DLA-1500-1, DLA-288-1 |
| Debian Bugs | 793616 |
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 | fixed |
| stretch (security) | 1:7.4p1-10+deb9u6 | fixed |
| stretch (lts), stretch | 1:7.4p1-10+deb9u9 | fixed |
| buster (security), buster, buster (lts) | 1:7.9p1-10+deb10u4 | fixed |
| bullseye (security), bullseye | 1:8.4p1-5+deb11u3 | fixed |
| bookworm (security), bookworm | 1:9.2p1-2+deb12u3 | fixed |
| sid, trixie | 1:9.9p1-3 | fixed |
The information below is based on the following data on fixed versions.
Notes
[wheezy] - openssh <no-dsa> (Minor issue; not in default configurations)
http://seclists.org/fulldisclosure/2015/Jul/92
Affects configurations that have KbdInteractiveAuthentication set
to yes. Default for KbdInteractiveAuthentication is to use whatever
value ChallengeResponseAuthentication is set to, which is 'no' in
default configurations in Debian.