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CVE-2025-34027

Versa Concerto Authentication Bypass File Write Remote Code Execution

Basic Information

CVE State
PUBLISHED
Reserved Date
April 15, 2025
Published Date
May 21, 2025
Last Updated
February 26, 2026
Vendor
Versa
Product
Concerto
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.
Tags
nuclei_scanner

CVSS Scores

CVSS v4.0

10.0 - CRITICAL

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

SSVC Information

Exploitation
none
Automatable
Yes
Technical Impact
total

Exploit Status

Exploited in the Wild
Yes (2025-08-01 00:00:00 UTC) Source

References

https://projectdiscovery.io/blog/versa-concerto-authentication-bypass-rce

Known Exploited Vulnerability Information

Source Added Date
The Shadowserver (via CIRCL) 2025-08-01 00:00:00 UTC

Scanner Integrations

Scanner URL Date Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-34027.yaml 2026-06-01 15:34:41 UTC

Timeline

  • CVE ID Reserved

  • CVE Published to Public

  • Added to KEVIntel

  • Detected by Nuclei