CVE-2016-20012
MEDIUMCVSS 5.3/10EPSS 5.04%
Last modified
CVE-2016-20012 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. OpenSSH through 8.7 allows remote attackers, who have a suspicion that a certain combination of username and public key is known to an SSH server, to test whether this suspicion is correct. This occurs because a challenge is sent only when that combination could be valid for a login session. EPSS estimates a 5.04% chance of exploitation in the next 30 days.
Description
OpenSSH through 8.7 allows remote attackers, who have a suspicion that a certain combination of username and public key is known to an SSH server, to test whether this suspicion is correct. This occurs because a challenge is sent only when that combination could be valid for a login session. NOTE: the vendor does not recognize user enumeration as a vulnerability for this product
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Openbsd | Openssh | <= 8.7 |
| Netapp | Clustered Data Ontap | All versions |
| Netapp | Hci Management Node | All versions |
| Netapp | Ontap Select Deploy Administration Utility | All versions |
| Netapp | Solidfire | All versions |
References
- https://github.com/openssh/openssh-portable/blob/d0fffc88c8fe90c1815c6f4097bc8cbcabc0f3dd/auth2-pubkey.c#L261-L265Exploit, Third Party Advisory
- https://github.com/openssh/openssh-portable/pull/270Patch, Third Party Advisory
- https://github.com/openssh/openssh-portable/pull/270#issuecomment-920577097Issue Tracking, Third Party Advisory
- https://github.com/openssh/openssh-portable/pull/270#issuecomment-943909185Issue Tracking, Third Party Advisory
- https://rushter.com/blog/public-ssh-keys/Exploit, Third Party Advisory
- https://security.netapp.com/advisory/ntap-20211014-0005/Third Party Advisory
- https://utcc.utoronto.ca/~cks/space/blog/tech/SSHKeysAreInfoLeakThird Party Advisory
- https://www.openwall.com/lists/oss-security/2018/08/24/1Mailing List, Third Party Advisory
- https://github.com/openssh/openssh-portable/blob/d0fffc88c8fe90c1815c6f4097bc8cbcabc0f3dd/auth2-pubkey.c#L261-L265Exploit, Third Party Advisory
- https://github.com/openssh/openssh-portable/pull/270Patch, Third Party Advisory
- https://github.com/openssh/openssh-portable/pull/270#issuecomment-920577097Issue Tracking, Third Party Advisory
- https://github.com/openssh/openssh-portable/pull/270#issuecomment-943909185Issue Tracking, Third Party Advisory
- https://rushter.com/blog/public-ssh-keys/Exploit, Third Party Advisory
- https://security.netapp.com/advisory/ntap-20211014-0005/Third Party Advisory
- https://utcc.utoronto.ca/~cks/space/blog/tech/SSHKeysAreInfoLeakThird Party Advisory
- https://www.openwall.com/lists/oss-security/2018/08/24/1Mailing List, Third Party Advisory
- https://github.com/openssh/openssh-portable/blob/d0fffc88c8fe90c1815c6f4097bc8cbcabc0f3dd/auth2-pubkey.c#L261-L265Exploit, Third Party Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2016-20012?
OpenSSH through 8.7 allows remote attackers, who have a suspicion that a certain combination of username and public key is known to an SSH server, to test whether this suspicion is correct. This occurs because a challenge is sent only when that combination could be valid for a login session. NOTE: the vendor does not recognize user enumeration as a vulnerability for this product
How severe is CVE-2016-20012?
CVE-2016-20012 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 5.04% probability of exploitation in the next 30 days.
How do I fix CVE-2016-20012?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2016
- CVE-2016-20007The REST/JSON project 7.x-1.x for Drupal allows session name…7.5
- CVE-2016-20008The REST/JSON project 7.x-1.x for Drupal allows session enum…7.5
- CVE-2016-20009A DNS client stack-based buffer overflow in ipdnsc_decode_na…9.8
- CVE-2016-2001HPE Universal CMDB Foundation 10.0, 10.01, 10.10, 10.11, and…
- CVE-2016-20010EWWW Image Optimizer before 2.8.5 allows remote command exec…10
- CVE-2016-20011libgrss through 0.7.0 fails to perform TLS certificate verif…7.5
- CVE-2016-20013sha256crypt and sha512crypt through 0.6 allow attackers to c…7.5
- CVE-2016-20014In pam_tacplus.c in pam_tacplus before 1.4.1, pam_sm_acct_mg…9.8
- CVE-2016-20015In the ebuild package through smokeping-2.7.3-r1 for SmokePi…7.5
- CVE-2016-20016MVPower CCTV DVR models, including TV-7104HE 1.8.4 115215B9 …9.8
- CVE-2016-20017D-Link DSL-2750B devices before 1.05 allow remote unauthenti…9.8
- CVE-2016-20018Knex Knex.js through 2.3.0 has a limited SQL injection vulne…7.5
Are you affected by CVE-2016-20012?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST