Cyber Resilience

CVE-2016-20012

MediumPublic PoCUpdated

Published: 15 September 2021

Published
15 September 2021
Modified
29 May 2026
KEV Added
Patch
CVSS Score v3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS Score 0.0865 92.6th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2016-20012 is a medium-severity Observable Discrepancy (CWE-203) vulnerability in Openbsd Openssh. Its CVSS base score is 5.3 (Medium).

Operationally, ranked in the top 7.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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…

more

when that combination could be valid for a login session. NOTE: the vendor does not recognize user enumeration as a vulnerability for this product

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

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

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-203

Misdirection can normalize or falsify responses to eliminate observable discrepancies that aid reconnaissance.

addresses: CWE-203

Observable discrepancies in system behavior can be modulated to create covert storage or timing channels; the required analysis detects and constrains such avenues.

addresses: CWE-203

Prevents attackers from using observable differences in error responses to infer internal system details or state.

References