CVE-2023-23914 in Enterprise Manager Ops Center
Summary
by MITRE • 02/23/2023
A cleartext transmission of sensitive information vulnerability exists in curl <v7.88.0 that could cause HSTS functionality fail when multiple URLs are requested serially. Using its HSTS support, curl can be instructed to use HTTPS instead of usingan insecure clear-text HTTP step even when HTTP is provided in the URL. ThisHSTS mechanism would however surprisingly be ignored by subsequent transferswhen done on the same command line because the state would not be properlycarried on.
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Analysis
by VulDB Data Team • 03/13/2025
The vulnerability identified as CVE-2023-23914 represents a critical cleartext transmission flaw in curl versions prior to v7.88.0 that undermines the security mechanisms designed to protect against man-in-the-middle attacks. This issue specifically targets the HTTP Strict Transport Security (HSTS) implementation within curl, which is intended to enforce secure HTTPS connections even when users specify HTTP URLs in their commands. The flaw manifests when multiple URLs are processed sequentially within the same command line execution, causing the HSTS state to be improperly maintained between transfers. This technical shortcoming creates a significant security gap where the application's attempt to enforce secure communication is bypassed, potentially exposing sensitive data to interception attacks.
The underlying technical mechanism of this vulnerability stems from how curl manages HSTS state persistence across multiple requests within a single execution context. When curl encounters the first URL in a sequence, it correctly applies HSTS rules and attempts to upgrade HTTP connections to HTTPS. However, during subsequent URL processing, the internal state management fails to preserve the HSTS configuration, resulting in a failure to enforce secure transport for following requests. This behavior violates the fundamental security principle of maintaining consistent security policies throughout a session, as defined in the CWE-319 category for cleartext transmission of sensitive information. The flaw essentially creates a race condition or state management issue where the security context established for one transfer is not properly propagated to subsequent transfers, leaving the application vulnerable to downgrade attacks.
The operational impact of this vulnerability extends beyond simple data exposure, as it undermines the trust model that secure web communication relies upon. When multiple URLs are requested serially, attackers can exploit this state inconsistency to force cleartext HTTP connections for subsequent transfers, potentially intercepting authentication tokens, session cookies, or other sensitive information. This vulnerability particularly affects automated scripts, security scanning tools, and any applications that rely on curl for sequential HTTP requests. The attack surface is further expanded when considering that HSTS is a critical component of modern web security protocols, as outlined in the ATT&CK framework under T1071.004 for application layer protocol. Organizations using curl for security-sensitive operations may unknowingly expose their systems to attacks that would otherwise be prevented by proper HSTS enforcement, creating a false sense of security while leaving critical communication channels vulnerable to eavesdropping.
Mitigation strategies for CVE-2023-23914 require immediate patching of curl installations to version 7.88.0 or later, where the HSTS state management has been corrected to properly maintain security context across multiple transfers. System administrators should conduct comprehensive inventory checks to identify all systems running vulnerable curl versions and prioritize remediation efforts. Additionally, organizations should implement monitoring solutions to detect unusual patterns in HTTP traffic that might indicate exploitation attempts. Network security controls such as deep packet inspection and protocol analysis tools can help identify cleartext transmissions that bypass expected HSTS behavior. The fix addresses the core issue by ensuring proper state persistence in the HSTS implementation, preventing the state loss that previously allowed subsequent transfers to ignore security policies established in earlier requests. Organizations should also consider implementing additional security layers such as network segmentation and traffic encryption at the application level to provide defense in depth against potential exploitation attempts.