CVE-2019-9191 in Enterprise Transport Security
Summary
by MITRE
The ETSI Enterprise Transport Security (ETS, formerly known as eTLS) protocol does not provide per-session forward secrecy.
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Analysis
by VulDB Data Team • 07/26/2023
The ETSI Enterprise Transport Security protocol represents a critical security vulnerability identified as CVE-2019-9191, where the implementation fails to incorporate per-session forward secrecy mechanisms. This weakness fundamentally undermines the cryptographic security posture of communications protected by the eTLS framework, creating persistent exposure risks for sensitive enterprise data transmissions. The vulnerability stems from the protocol's design philosophy that prioritizes compatibility and ease of deployment over robust cryptographic security principles, leaving organizations vulnerable to long-term data compromise.
The technical flaw manifests in the protocol's inability to establish unique cryptographic keys for each communication session, instead relying on static key material that remains consistent across multiple connections. This design choice directly violates fundamental cryptographic best practices and aligns with CWE-326, which specifically addresses the absence of proper encryption strength and key management. When attackers intercept network traffic, they can potentially store encrypted communications and later decrypt them once they obtain the static keys, effectively nullifying the security benefits that should be provided by transport layer encryption.
The operational impact of this vulnerability extends beyond simple data exposure risks to encompass comprehensive enterprise security degradation. Organizations utilizing ETSI ETS/ETLS protocols become susceptible to sophisticated attacks where adversaries can accumulate encrypted traffic over extended periods and then exploit the lack of forward secrecy to access historical communications. This creates a persistent threat vector that can compromise sensitive business information, intellectual property, and confidential communications. The vulnerability particularly affects enterprise environments where long-term data retention and security compliance are critical requirements.
Security professionals must recognize that this weakness creates an environment where attackers can perform advanced persistent threat operations, storing encrypted communications and decrypting them at their convenience rather than being limited to real-time interception attacks. The vulnerability directly impacts the confidentiality and integrity of enterprise communications, potentially violating regulatory compliance requirements under standards such as pci dss, hipaa, and gdpr. Organizations should implement immediate mitigations including protocol migration to alternatives that provide proper forward secrecy, such as tls 1.3 implementations, and consider network segmentation to limit exposure. The ATT&CK framework categorizes this vulnerability under credential access and defense evasion techniques, as it enables attackers to maintain access to encrypted communications over extended periods while avoiding detection through normal security monitoring.