CVE-2025-34027
CVE-2025-34027 is a critical-severity vulnerability with a CVSS 4.0 base score of 10.0. Its EPSS exploit-prediction score of 36% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-367.
Key facts
- Severity: Critical (CVSS 4.0 base score 10.0)
- EPSS exploit prediction: 36% (98th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2025-16088
- Weakness: CWE-367
- Published:
- Last modified:
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.
Frequently asked questions
- What is 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.
- How severe is CVE-2025-34027?
- CVE-2025-34027 has a CVSS 4.0 base score of 10.0, rated critical severity.
- Is CVE-2025-34027 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 36% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2025-34027?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- Does CVE-2025-34027 have an EU (EUVD) identifier?
- Yes. CVE-2025-34027 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-16088.
- When was CVE-2025-34027 published?
- CVE-2025-34027 was published on 2025-05-21 and last updated on 2026-06-17.
References
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