GHSA-gmhj-xjfh-cf6m
Caddy-SSH vulnerable to Authorization Bypass due to incorrect usage of PAM library
GHSA-gmhj-xjfh-cf6m is a high vulnerability (CVSS 7.7) in github.com/mohammed90/caddy-ssh, published September 23, 2022. No source lists public exploit code. No source names a fixed version.
- Severity
- 7.7 HighCVSS 3.1, GitHub Advisories
- Exploit chance
- UnscoredNo EPSS score yet
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
- No fix listedNo source names one
Description
Not invoking a call to pam_acct_mgmt after a call to pam_authenticate to check the validity of a login can lead to an authorization bypass.
Impact
Exploitability
The attack can be carried over the network. A complex non-standard configuration or a specialized condition is required for the attack to be successfully conducted. The attacker also requires access to a users credentials, be it expired, for an attack to be successful. There is no user interaction required for successful execution. The attack can affect components outside the scope of the target module.
Impact
Using this attack vector, an attacker may access otherwise restricted parts of the system. The attack can be used to gain access to confidential files like passwords, login credentials and other secrets. Hence, it has a high impact on confidentiality. It may also be directly used to affect a change on a system resource. Hence has a medium to high impact on integrity. This attack may not be used to affect the availability of the system. Taking this account an appropriate CVSS v3.1 vector would be AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N
Root Cause Analysis
In this case, in the following PAM transaction, only a call to pam.Authenticate is used to login a user.
This implies that a user with expired credentials can still login.
The bug can be verified easily by creating a new user account, expiring it with chage -E0 <username> and then trying to log in with the expired credentials.
Patches
This can be fixed by invoking a call to pam.AcctMgmt after a successful call to pam.Authenticate
References
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/mohammed90/caddy-sshGo | 0.0.1 to 0.0.1 | None known |
github.com/mohammed90/caddy-sshGo | Listed versions 0.0.1 | None known |
What each source reports
GitHub Advisories Score used
Caddy-SSH vulnerable to Authorization Bypass due to incorrect usage of PAM library
Not invoking a call to pam_acct_mgmt after a call to pam_authenticate to check the validity of a login can lead to an authorization bypass.
Impact
Exploitability
The attack can be carried over the network. A complex non-standard configuration or a specialized condition is required for the attack to be successfully conducted. The attacker also requires access to a users credentials, be it expired, for an attack to be successful. There is no user interaction required for successful execution. The attack can affect components outside the scope of the target module.
Impact
Using this attack vector, an attacker may access otherwise restricted parts of the system. The attack can be used to gain access to confidential files like passwords, login credentials and other secrets. Hence, it has a high impact on confidentiality. It may also be directly used to affect a change on a system resource. Hence has a medium to high impact on integrity. This attack may not be used to affect the availability of the system. Taking this account an appropriate CVSS v3.1 vector would be AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N
Root Cause Analysis
In this case, in the following PAM transaction, only a call to pam.Authenticate is used to login a user.
This implies that a user with expired credentials can still login.
The bug can be verified easily by creating a new user account, expiring it with chage -E0 <username> and then trying to log in with the expired credentials.
Patches
This can be fixed by invoking a call to pam.AcctMgmt after a successful call to pam.Authenticate
References
- Record
GHSA-gmhj-xjfh-cf6m- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:N - Weakness
- CWE-287
- Updated
- 2026-11-02
OSV
Caddy-SSH vulnerable to Authorization Bypass due to incorrect usage of PAM library
Not invoking a call to pam_acct_mgmt after a call to pam_authenticate to check the validity of a login can lead to an authorization bypass.
Impact
Exploitability
The attack can be carried over the network. A complex non-standard configuration or a specialized condition is required for the attack to be successfully conducted. The attacker also requires access to a users credentials, be it expired, for an attack to be successful. There is no user interaction required for successful execution. The attack can affect components outside the scope of the target module.
Impact
Using this attack vector, an attacker may access otherwise restricted parts of the system. The attack can be used to gain access to confidential files like passwords, login credentials and other secrets. Hence, it has a high impact on confidentiality. It may also be directly used to affect a change on a system resource. Hence has a medium to high impact on integrity. This attack may not be used to affect the availability of the system. Taking this account an appropriate CVSS v3.1 vector would be AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N
Root Cause Analysis
In this case, in the following PAM transaction, only a call to pam.Authenticate is used to login a user.
This implies that a user with expired credentials can still login.
The bug can be verified easily by creating a new user account, expiring it with chage -E0 <username> and then trying to log in with the expired credentials.
Patches
This can be fixed by invoking a call to pam.AcctMgmt after a successful call to pam.Authenticate
References
- Record
GHSA-gmhj-xjfh-cf6m- CVSS 3.1
- 7.7 High
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:N - Weakness
- CWE-287
- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | GitHub Advisories, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.