SB20260814127 - Multiple vulnerabilities in nginx-ui

Description

This security bulletin contains information about 2 vulnerabilities.

1) Insufficient Session Expiration (CVE-ID: N/A)

CWE-ID: CWE-613 - Insufficient Session Expiration

CVSSv4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a remote user to regain access using a previously revoked short token.

The vulnerability exists due to insufficient session expiration in short-token cache handling when processing short-token authentication after an account is re-enabled. A remote user can reuse a previously revoked short token to regain access using a previously revoked short token.

This affects standalone short tokens used for WebSocket and explicit-token authentication, and exploitation requires the account to be re-enabled before the cached token entry expires.

2) Authentication bypass using an alternate path or channel (CVE-ID: N/A)

CWE-ID: CWE-288 - Authentication Bypass Using an Alternate Path or Channel

CVSSv4: 7.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote user to bypass the secure-session step-up requirement and modify Nginx configuration.

The vulnerability exists due to authentication bypass using an alternate path or channel in the /mcp and /mcp_message MCP endpoints when handling configuration mutation requests. A remote user can use the nginx_config_add or nginx_config_modify tools through the MCP interface to bypass the secure-session step-up requirement and modify Nginx configuration.

Only OTP-enabled accounts are affected, and exploitation requires the MCP feature to be enabled.

Remediation

Install update from vendor's website.

References

• https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-wq4w-vwvq-q3x9
• https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-vc32-4gwf-77xp