Full Report
Critical vulnerabilities in Versa Concerto that are still unpatched could allow remote attackers to bypass authentication and execute arbitrary code on affected systems. [...]
Analysis Summary
# Vulnerability: Multiple Critical Flaws in Versa Concerto (Auth Bypass, RCE)
## CVE Details
- CVE ID: **CVE-2025-34027** (Implied based on context of RCE via race condition/file upload)
- CVSS Score: **Not explicitly provided** for CVE-2025-34027, but described as critical.
- CWE: **CWE-362: Race Condition** (Inferred from technical description)
- CVE ID: **CVE-2025-34026**
- CVSS Score: **9.2/10 (Critical)**
- CWE: **CWE-287: Improper Authentication** (Inferred from "improper reliance" and access control bypass)
- CVE ID: **CVE-2025-34025**
- CVSS Score: **8.6 (High)**
- CWE: **CWE-284: Improper Access Control** (Inferred from exposed host binaries)
## Affected Systems
- Products: **Versa Concerto**
- Versions: **All affected releases** (Specific versions not listed, but hotfixes were intended for all)
- Configurations:
* CVE-2025-34026: Systems using a Traefik proxy that forwards the `X-Real-Ip` header improperly.
* CVE-2025-34025: Misconfigured Docker setup exposing host binaries to container writes.
## Vulnerability Description
The article details several unpatched vulnerabilities discovered by ProjectDiscovery in Versa Concerto:
1. **Authentication Bypass/RCE (Associated with CVE-2025-34027):** Exploiting a race condition vulnerability related to an authentication mechanism and access to a file upload endpoint. Successful exploitation allows an attacker to write malicious files to disk and achieve Remote Code Execution (RCE) using `ld.so.preload` and establishing a reverse shell.
2. **SSRF/Actuator Access Bypass (CVE-2025-34026):** An improper reliance on the `X-Real-Ip` header allows attackers to bypass access controls to sensitive Spring Boot Actuator endpoints (e.g., by suppressing the header via a Traefik proxy trick). This can lead to credential and session token extraction.
3. **Host Binary Overwrite (CVE-2025-34025):** A misconfigured Docker setup permits containerized processes to overwrite host binaries (like `/usr/bin/test`). If an attacker writes a reverse shell script to a host binary, a subsequent host cron job execution leads to full host compromise.
## Exploitation
- Status: **PoC available** (Researchers created a video demonstrating CVE-2025-34027 exploitation)
- Complexity: **Not explicitly detailed**, but exploiting a race condition (CVE-2025-34027) suggests **Medium/High** complexity; Actuator bypass (CVE-2025-34026) suggests **Low/Medium**.
- Attack Vector: **Network** (Implied for RCE and Actuator access); **Container/Local** (For Docker overwrite leading to host execution).
## Impact
- Confidentiality: **High** (Credential and session token extraction possible via CVE-2025-34026)
- Integrity: **Critical** (Remote Code Execution possible via CVE-2025-34027 and CVE-2025-34025)
- Availability: **High** (Implied due to RCE allowing system compromise)
## Remediation
### Patches
- **No official patch is currently available.** Versa Networks indicated hotfixes would be available April 7th but subsequently stopped responding to researchers. Users must rely on temporary mitigations.
### Workarounds
- Block semicolons in URLs via a reverse proxy or Web Application Firewall (WAF).
- Drop requests that contain `Connection: X-Real-Ip` to block abuse of the Actuator access control bypass.
## Detection
- **Detection Methods:** Monitor for unusual connection attempts utilizing semicolons in URLs or requests containing the `Connection: X-Real-Ip` header reaching the Versa Concerto application, potentially indicating exploitation attempts against CVE-2025-34026.
- **Indicators of Compromise:** Look for unexpected modifications of system binaries on the host, or unauthorized reverse shell connections originating from the environment hosting Versa Concerto components.
## References
- Vendor Advisories: **None publically confirmed** following the disclosure deadline expiration.
- Relevant links:
* bleepingcomputer com/news/security/unpatched-critical-bugs-in-versa-concerto-lead-to-auth-bypass-rce/