Vulnerability Name:

CVE-2019-7639 (CCN-156763)

Assigned:2019-02-08
Published:2019-02-08
Updated:2020-08-24
Summary:An issue was discovered in gsi-openssh-server 7.9p1 on Fedora 29. If PermitPAMUserChange is set to yes in the /etc/gsissh/sshd_config file, logins succeed with a valid username and an incorrect password, even though a failure entry is recorded in the /var/log/messages file.
CVSS v3 Severity:8.1 High (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)
7.1 High (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): High
Availibility (A): High
7.5 High (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N)
6.5 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): High
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
7.8 High (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:C/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): Complete
Availibility (A): None
Vulnerability Type:CWE-863
Vulnerability Consequences:Bypass Security
References:Source: MITRE
Type: CNA
CVE-2019-7639

Source: CCN
Type: Fedora Web site
security update in Fedora 29 for gsi-openssh

Source: CCN
Type: Red Hat Bugzilla – Bug 1673802
Enabling PermitPAMUserChange allows to login with the correct username and wrong password

Source: MISC
Type: Exploit, Issue Tracking, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1673802

Source: XF
Type: UNKNOWN
gsiopenssh-cve20197639-sec-bypass(156763)

Vulnerable Configuration:Configuration 1:
  • cpe:/o:fedoraproject:fedora:28:*:*:*:*:*:*:*
  • OR cpe:/o:fedoraproject:fedora:29:*:*:*:*:*:*:*

    • Configuration 2:
  • cpe:/a:gsi-openssh_project:gsi-openssh:7.9:p1:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    BACK
    fedoraproject fedora 28
    fedoraproject fedora 29
    gsi-openssh_project gsi-openssh 7.9 p1