Description

gitoxide before 0.38.2 fails to validate carriage return characters in URL values passed to credential helpers. Attackers can supply URLs containing bare carriage returns to inject additional helper protocol fields and cause credential helpers to return credentials for attacker-specified hosts instead of the requested URL.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "3.1",
  "pubDate": "2026-08-28T12:16:36.810Z",
  "pubdate": "2026-08-28T12:16:36.810Z",
  "executiveSummary": "The vulnerability identified in gitoxide versions prior to 0.38.2 concerns an improper input validation flaw within the handling of URL values passed to credential helpers.\nThis vulnerability is classified as a protocol injection flaw, where the lack of sanitization for carriage return (CR) characters allows an attacker to manipulate the communication stream between the git client and the credential helper.\nBy injecting newline-based control characters, an attacker can effectively perform 'helper command injection,' leading to the redirection of authentication credentials.\nThe primary impact is the unauthorized disclosure of sensitive credentials, as the helper is tricked into returning credentials meant for the legitimate host to an attacker-controlled endpoint or context.\nThis affects all gitoxide-based applications that utilize external credential helpers. Successful exploitation requires the ability to influence the URL provided to the credential helper, typically through malicious repository configuration or cloned URLs.\nThe risk is critical for environments relying on gitoxide for secure repository interactions, as it facilitates credential exfiltration without requiring elevated privileges on the victim's host, provided the attacker can influence the URL input parameters.",
  "technicalDetails": "The root cause of this vulnerability lies in the insufficient sanitization of URL strings within gitoxide before version 0.38.2. When gitoxide interfaces with external credential helpers, it transmits protocol-specific fields, such as 'url', to the helper executable via standard input/output streams.\nThe credential helper protocol generally relies on a line-based format where key-value pairs are separated by newlines. Because the URL value is not stripped of carriage return (CR, ASCII 0x0D) or line feed (LF, ASCII 0x0A) characters, an attacker can perform a credential helper injection attack.\nAn attacker can construct a malicious URL string containing CR characters (e.g., 'https://trusted.com\r\nhost=attacker.com\r\n\r\n'). When this string is processed, the gitoxide client passes the payload directly to the helper. The credential helper interprets the injected CR sequence as the end of the 'url' field and the beginning of new, attacker-defined fields.\nBy injecting 'host=attacker.com', the attacker manipulates the helper into responding to the request as if it were authenticating against the attacker's specified domain rather than the legitimate one intended by the user.\nThe attack flow follows these steps: 1) The attacker convinces a user to interact with a malicious repository URL containing the injection payload. 2) gitoxide invokes the credential helper and populates the protocol fields with the unsanitized URL string. 3) The helper parses the injected CR sequence, triggering an unexpected field overwrite or addition. 4) The credential helper process retrieves and returns credentials associated with the attacker-controlled host identifier. 5) The sensitive authentication tokens are leaked to the attacker's endpoint.\nThis vulnerability does not require authentication or specific privileges on the local machine; it is purely a function of input handling logic within the gitoxide codebase. The flaw persists in any scenario where an external helper is invoked and the input URL is controlled by an unauthenticated source or a malicious repository configuration file (e.g., .git/config). Post-exploitation impact includes the full compromise of user credentials stored within the system's credential manager, leading to unauthorized access to private repositories or internal services."
}