Unauthorized session access via identifiers in URLs
Published Jul 8, 2025 · Updated May 12, 2026
Sensitive data exposure in Siemens SIPROTEC 5 devices allows remote attackers to obtain session identifiers from stored URLs. Certain web functions place session identifiers in URL query strings, causing browsers, proxies, and logs to retain authentication material. Exploitation requires user interaction with an affected function and access to stored URL data; recovered identifiers enable unauthorized session access.
Summary
What happened
Sensitive data exposure in Siemens SIPROTEC 5 devices allows remote attackers to obtain session identifiers from stored URLs. Certain web functions place session identifiers in URL query strings, causing browsers, proxies, and logs to retain authentication material. Exploitation requires user interaction with an affected function and access to stored URL data; recovered identifiers enable unauthorized session access.
The record
- CVE
- CVE-2025-40742
- Published
- Jul 8, 2025
- Updated
- May 12, 2026
- Vendor
- Siemens
- Product
- SIPROTEC 5 6MD86 (CP300)
- Classifications
- CWE-598, T1539
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 8, 2025CVE publishedPublication date reported by the CVE source.
- May 12, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <V11.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo