Vulnerability Intelligence Report
Versa Concerto Authentication Bypass File Write Remote Code Execution
CVE-2025-34027
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.
Nuclei Template
CVSS Base Score
10.0
CRITICAL
EPSS Probability:34.58%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
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Authentication
—
Weaponization
—
SSVC Action
—
Weaknesses (CWE)
CWE-367 ↗CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| Versa | Concerto | 12.1.2 <= 12.2.0 (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | VulnCheck · Bug Bounty Provider · USA |
| Reserved | 2025-04-15T19:15:22 |
| Published | 2025-05-21T21:58:31 |
| Last Updated | 2026-02-26T18:27:59 |
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