Vulnerability Name:

CVE-2021-36367 (CCN-205168)

Assigned:2021-06-19
Published:2021-06-19
Updated:2021-07-14
Summary:PuTTY through 0.75 proceeds with establishing an SSH session even if it has never sent a substantive authentication response. This makes it easier for an attacker-controlled SSH server to present a later spoofed authentication prompt (that the attacker can use to capture credential data, and use that data for purposes that are undesired by the client user).
CVSS v3 Severity:8.1 High (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N)
7.1 High (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): Required
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): High
Availibility (A): None
8.1 High (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N)
7.1 High (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): Required
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): High
Availibility (A): None
CVSS v2 Severity:5.8 Medium (CVSS v2 Vector: AV:N/AC:M/Au:N/C:P/I:P/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Medium
Authentication (Au): None
Impact Metrics:Confidentiality (C): Partial
Integrity (I): Partial
Availibility (A): None
8.5 High (CCN CVSS v2 Vector: AV:N/AC:L/Au:S/C:C/I:C/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): Single_Instance
Impact Metrics:Confidentiality (C): Complete
Integrity (I): Complete
Availibility (A): None
Vulnerability Type:CWE-345
Vulnerability Consequences:Obtain Information
References:Source: MITRE
Type: CNA
CVE-2021-36367

Source: XF
Type: UNKNOWN
putty-cve202136367-info-disc(205168)

Source: CCN
Type: PuTTY GIT Repository
New option to reject 'trivial' success of userauth

Source: MISC
Type: Mailing List, Patch, Third Party Advisory
https://git.tartarus.org/?p=simon/putty.git;a=commit;h=1dc5659aa62848f0aeb5de7bd3839fecc7debefa

Source: MISC
Type: Release Notes, Third Party Advisory
https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html

Vulnerable Configuration:Configuration 1:
  • cpe:/a:putty:putty:*:*:*:*:*:*:*:* (Version <= 0.75)

    • Configuration CCN 1:
  • cpe:/a:putty:putty:0.75:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    BACK
    putty putty *
    putty putty 0.75