Vulnerability Name:

CVE-2016-20012 (CCN-209534)

Assigned:2019-11-29
Published:2019-11-29
Updated:2022-04-18
Summary:** DISPUTED ** 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.
CVSS v3 Severity:5.3 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N)
4.8 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:P/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): Low
Integrity (I): None
Availibility (A): None
5.3 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N)
4.8 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:P/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): Low
Integrity (I): None
Availibility (A): None
CVSS v2 Severity:4.3 Medium (CVSS v2 Vector: AV:N/AC:M/Au:N/C:P/I:N/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Medium
Authentication (Au): None
Impact Metrics:Confidentiality (C): Partial
Integrity (I): None
Availibility (A): None
5.0 Medium (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:P/I:N/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): Partial
Integrity (I): None
Availibility (A): None
Vulnerability Type:CWE-Other
Vulnerability Consequences:Obtain Information
References:Source: MITRE
Type: CNA
CVE-2016-20012

Source: XF
Type: UNKNOWN
openssh-cve201620012-info-disc(209534)

Source: CCN
Type: OpenSSH GIT Repository
openssh-portable

Source: MISC
Type: Exploit, Third Party Advisory
https://github.com/openssh/openssh-portable/blob/d0fffc88c8fe90c1815c6f4097bc8cbcabc0f3dd/auth2-pubkey.c#L261-L265

Source: CCN
Type: openssh-portable GIT REpository
CVE-2016-20012 - Publickey Information leak - Only allow SSH_MSG_USERAUTH_REQUEST with signature #270

Source: MISC
Type: Patch, Third Party Advisory
https://github.com/openssh/openssh-portable/pull/270

Source: MISC
Type: Issue Tracking, Third Party Advisory
https://github.com/openssh/openssh-portable/pull/270#issuecomment-920577097

Source: MISC
Type: Issue Tracking, Third Party Advisory
https://github.com/openssh/openssh-portable/pull/270#issuecomment-943909185

Source: MISC
Type: Exploit, Third Party Advisory
https://rushter.com/blog/public-ssh-keys/

Source: CONFIRM
Type: Third Party Advisory
https://security.netapp.com/advisory/ntap-20211014-0005/

Source: MISC
Type: Third Party Advisory
https://utcc.utoronto.ca/~cks/space/blog/tech/SSHKeysAreInfoLeak

Source: MISC
Type: Mailing List, Third Party Advisory
https://www.openwall.com/lists/oss-security/2018/08/24/1

Vulnerable Configuration:Configuration 1:
  • cpe:/a:openbsd:openssh:*:*:*:*:*:*:*:* (Version <= 8.7)

  • Configuration 2:
  • cpe:/a:netapp:clustered_data_ontap:-:*:*:*:*:*:*:*
  • OR cpe:/a:netapp:hci_management_node:-:*:*:*:*:*:*:*
  • OR cpe:/a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:*
  • OR cpe:/a:netapp:solidfire:-:*:*:*:*:*:*:*

  • Configuration CCN 1:
  • cpe:/a:openbsd:openssh:8.7:-:*:*:*:*:*:*

  • * Denotes that component is vulnerable
    BACK
    openbsd openssh *
    netapp clustered data ontap -
    netapp hci management node -
    netapp ontap select deploy administration utility -
    netapp solidfire -
    openbsd openssh 8.7 -