CVE-2026-33032: Nginx UI Authentication Bypass Enables Unauthenticated Server Takeover (CVSS 9.8)

Remote authenticated attackers can achieve arbitrary command execution on nginx-ui v2.3.3 servers by manipulating encrypted backup archives during restoration. The vulnerability stems from a circular trust model where backup integrity metadata is encrypted using the same AES key provided to clients, allowing attackers to decrypt backups, inject malicious configuration (including command execution directives), recompute valid hashes, and re-encrypt the archive. The restore process accepts tampered backups despite hash verification warnings. Publicly available exploit code exists with detailed proof-of-concept demonstrating configuration injection leading to arbitrary command execution. Vendor-released patch available in nginx-ui v2.3.4. This represents a regression from GHSA-g9w5-qffc-6762, which addressed backup access control but not the underlying cryptographic design flaw.

Insecure Direct Object Reference (IDOR) in nginx-ui up to v2.3.3 allows authenticated low-privilege users to access, modify, and delete any resource across all user accounts, including plaintext DNS provider API tokens (Cloudflare, AWS Route53, Alibaba Cloud) and ACME private keys. The application's base Model struct lacks user_id fields, and all resource endpoints query by ID without ownership verification. CVSS 8.8 reflects scope change to external services—stolen Cloudflare tokens enable DNS hijacking and fraudulent certificate issuance. No public exploit identified at time of analysis, but trivial to execute via standard HTTP requests. Vendor-released patch: v2.3.4.

Race condition in nginx-ui web interface allows remote authenticated attackers to corrupt the primary configuration file (app.ini) through concurrent API requests, resulting in persistent denial of service and potential remote code execution. The vulnerability affects nginx-ui versions prior to 2.3.4 deployed in production environments including Docker containers. Concurrent POST requests to /api/settings trigger unsynchronized file writes that interleave at the OS level, corrupting configuration sections and creating cross-contamination between INI fields. In non-deterministic scenarios, user-controlled input can overwrite shell command fields (ReloadCmd, RestartCmd), enabling arbitrary command execution during nginx reload operations. Public exploit code demonstrates the attack path using standard HTTP testing tools. No CISA KEV listing or EPSS data available at time of analysis, but proof-of-concept with detailed reproduction steps exists in the GitHub security advisory.

Authenticated users in nginx-ui v2.3.3 and earlier can delete the entire `/etc/nginx` configuration directory via path traversal using double-encoded sequences (..%252F), causing immediate Nginx service failure and denial of service. The vulnerability exploits improper URL canonicalization combined with unsafe recursive deletion logic that resolves malicious paths to the base configuration directory instead of rejecting them.

Authenticated denial of service in nginx-ui 2.3.3 and earlier allows any user with settings access to submit a negative integer for the logrotate.interval parameter, triggering an infinite loop in the backend that exhausts CPU resources and renders the web interface unresponsive. Vendor-released patch available in v2.3.4. No public exploit code identified beyond proof-of-concept documentation; not confirmed as actively exploited.