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

Overview

Severity

Medium (CVSS 5.3)

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Exploit Status

Not Exploited

Patch Tuesday

2021-Sep

Released

2021-10-01

EPSS Score

14.60% (percentile: 94.5%)

FAQ

Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability? One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.

Detection & Weaponization (1 sources)

Maturity: Exploit

• GitHub PoC: 1 repositories

Affected Products (1)

Other

• 16862-16820

Revision History

• 2021-10-01: Information published.