Description

openssl_encrypt versions before 1.4.9 fail to validate server URLs in login and register_with_email functions, accepting unencrypted http:// URLs and unconfigured hosts. Attackers on the network path can intercept cleartext credentials including client_id, passwords, and JWTs to achieve full keyserver account takeover.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.5",
  "pubDate": "2026-08-27T17:20:58.993Z",
  "pubdate": "2026-08-27T17:20:58.993Z",
  "executiveSummary": "The openssl_encrypt library, in versions prior to 1.4.9, exhibits a critical vulnerability stemming from insufficient validation of server URLs during authentication and registration workflows. Specifically, the login and register_with_email functions fail to enforce transport layer security, permitting the use of unencrypted http:// protocols and arbitrary, unconfigured hostnames.\nThis flaw exposes sensitive authentication data to passive or active network adversaries. An attacker positioned on the network path—such as an entity performing a Man-in-the-Middle (MitM) attack—can intercept cleartext credentials, including client_id strings, user passwords, and sensitive JWTs. Successful exploitation results in complete keyserver account takeover, bypassing the intended security controls of the authentication process. The vulnerability presents a severe risk to confidentiality and integrity, as it allows unauthorized access to user accounts without requiring advanced exploitation techniques beyond network interception capabilities.",
  "technicalDetails": "The root cause of this vulnerability is an improper implementation of URL handling logic within the openssl_encrypt library. The affected functions, specifically login and register_with_email, fail to implement strict allow-listing or protocol enforcement for the target server endpoint. Because the library accepts user-supplied or inadequately validated host URLs, the application layer does not force the transition to encrypted transport protocols (e.g., https://), relying instead on insecure http:// connections by default.\nThe exploitation flow begins when an application utilizing the vulnerable library initiates a communication request to a keyserver. An attacker positioned on the network path (e.g., via ARP spoofing, DNS hijacking, or compromised network infrastructure) intercepting the traffic can manipulate the connection or simply observe the cleartext data stream. Because the library fails to validate that the connection is encrypted, the attacker captures the transmitted data, which includes raw client credentials, passwords, and JSON Web Tokens (JWTs).\nOnce these tokens or credentials are intercepted, the attacker can conduct a full account takeover. The JWTs, if captured before expiration, allow the attacker to impersonate the client session to the keyserver. Furthermore, the ability to specify unconfigured hosts allows for redirection to an attacker-controlled server, facilitating credential harvesting and sophisticated session injection attacks. This vulnerability effectively negates the security mechanisms provided by the cryptographic library by failing to secure the transport layer before data transmission occurs.\nAffected versions are strictly limited to those preceding 1.4.9. The vulnerability is exploitable without prior authentication, as the flaw occurs during the very processes intended to establish identity and security. There are no privilege requirements for the attacker, provided they have a vantage point on the network path between the client application and the target keyserver. The impact extends to all users of the affected library versions, necessitating immediate updates to a non-vulnerable version to enforce secure transport and proper host validation."
}