Authentication data disclosure via predictable AES key derivation
Published Sep 5, 2023 · Updated Feb 13, 2025
Authentication bypass in OAS Engine in Open Automation Software OAS Platform 18.00.0072 allows man-in-the-middle attackers to decrypt authentication data. The U_EP protobuf derives its AES-CBC key from a transmitted seed, a fixed subtraction, and a hard-coded base key, then decrypts with a null initialization vector. Access to captured configuration traffic exposes the serialized username and encrypted password, while integrity and service availability remain unaffected.
Summary
What happened
Authentication bypass in OAS Engine in Open Automation Software OAS Platform 18.00.0072 allows man-in-the-middle attackers to decrypt authentication data. The U_EP protobuf derives its AES-CBC key from a transmitted seed, a fixed subtraction, and a hard-coded base key, then decrypts with a null initialization vector. Access to captured configuration traffic exposes the serialized username and encrypted password, while integrity and service availability remain unaffected.
The record
- CVE
- CVE-2023-34353
- Published
- Sep 5, 2023
- Updated
- Feb 13, 2025
- Vendor
- Open Automation Software
- Product
- OAS Platform
- Classifications
- CWE-330, T1040
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 5, 2023CVE publishedPublication date reported by the CVE source.
- Feb 13, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=v18.00.0072
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.
Public exploit references
- U_EP AES-CBC decryption procedureproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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