Description
The key_certify function in usr.bin/ssh/key.c in OpenSSH 5.6 and 5.7, when generating legacy certificates using the -t command-line option in ssh-keygen, does not initialize the nonce field, which might allow remote attackers to obtain sensitive stack memory contents or make it easier to conduct hash collision attacks.
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 | openssh | 1:5.8p1-2 | — |
| Debian 13 | openssh | 1:5.8p1-2 | — |
| Debian 12 | openssh | 1:5.8p1-2 | — |
References
- [oss-security] 20110204 Re: [vendor-sec] OpenSSH security advisory: legacy certificate signing in 5.6/5.7 mailing-list
- 1025028 vdb-entry
- 46155 vdb-entry
- http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10673
- ADV-2011-0284 vdb-entry
- 43181 third-party-advisory
- HPSBMA02658 vendor-advisory
- 44269 third-party-advisory
- http://www.openssh.com/txt/legacy-cert.adv
- openssh-certificate-info-disclosure(65163) vdb-entry