CVE-2017-9735 in Communications Cloud Native Core Policy
Summary
by MITRE
Jetty through 9.4.x is prone to a timing channel in util/security/Password.java, which makes it easier for remote attackers to obtain access by observing elapsed times before rejection of incorrect passwords.
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Analysis
by VulDB Data Team • 08/19/2024
The vulnerability identified as CVE-2017-9735 affects Apache Jetty versions prior to 9.4.x and represents a significant security flaw in the password validation mechanism. This timing channel vulnerability exists within the util/security/Password.java component of the web server software, creating a predictable pattern that attackers can exploit to bypass authentication systems. The flaw stems from inconsistent response times when processing authentication attempts, where valid passwords take a different amount of time to process compared to invalid ones, thereby leaking information about the correctness of submitted credentials.
The technical implementation of this vulnerability occurs in the password comparison logic where the system does not employ constant-time string comparison methods. When an incorrect password is submitted, the system takes a measurable amount of time to process the comparison and reject the attempt, while valid passwords require slightly less time due to the early termination of the comparison process. This differential timing creates a side-channel attack vector that allows malicious actors to perform statistical analysis on response times and gradually deduce valid credentials through brute force or dictionary attacks. The vulnerability is particularly dangerous in environments where attackers can make multiple authentication attempts and observe the timing variations between successful and failed authentication requests.
The operational impact of this vulnerability extends beyond simple credential theft, as it enables sophisticated attack patterns that can be automated to systematically uncover valid passwords without triggering account lockout mechanisms. Attackers can leverage this timing information to perform password guessing attacks with significantly reduced effort compared to traditional methods, as they can eliminate incorrect password candidates based on timing observations rather than relying solely on trial and error. This weakness particularly affects systems where Jetty serves as a web application container and where authentication is critical for protecting sensitive data or administrative functions, making it a prime target for credential harvesting attacks in enterprise environments.
Mitigation strategies for CVE-2017-9735 require immediate implementation of constant-time comparison algorithms throughout the authentication stack, ensuring that all password validation operations take the same amount of time regardless of whether the input matches the expected value. Organizations should upgrade to Jetty 9.4.x or later versions where this vulnerability has been addressed through proper implementation of timing-attack resistant password comparison functions. Security teams should also implement additional layers of protection including account lockout policies, rate limiting, and multi-factor authentication to reduce the effectiveness of timing-based attacks even if the primary vulnerability is not immediately patched. The weakness aligns with CWE-320 and follows patterns described in ATT&CK technique T1110 for credential access through timing attacks, emphasizing the need for comprehensive security measures that address both the immediate vulnerability and broader authentication security practices.