CVE-2025-34027

CVE-2025-34027 is a critical-severity vulnerability in Versa-networks Concerto with a CVSS 3.x base score of 9.0. Its EPSS exploit-prediction score of 45% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-367.

Key facts

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 3.x base score of 9.0, rated critical severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-34027 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 45% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-34027?
CVE-2025-34027 primarily affects Versa-networks Concerto. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
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 2026-08-25.

References

Affected products (3)

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