Vulnerability · Published May 21, 2025 · Assigned by VulnCheck
CVE-2025-34027Versa Concerto Authentication Bypass File Write Remote Code Execution
Critical 10.0
In plain English
A critical-severity security flaw in Concerto from Versa. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 46.4% (higher than 99% of all known vulnerabilities). Ready-made attack tooling exists: Nuclei.
Official description
The Versa Concerto SD-WAN orchestration platform is vulnerable to an authentication bypass in the Traefik reverse proxy configuration, allowing at attacker to access administrative endpoints. The Spack upload endpoint can be leveraged for a Time-of-Check to Time-of-Use (TOCTOU) write in combination with a race condition to achieve remote code execution via path loading manipulation, allowing an unauthenticated actor to achieve remote code execution (RCE).This issue is known to affect Concerto from 12.1.2 through 12.2.0. Additional versions may be vulnerable.
Affected products (as reported)
Weakness: CWE-367 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L
References
- https://projectdiscovery.io/blog/versa-concerto-authentication-bypass-rce exploit, mitigation