CVE-2024-39694 pertains to a vulnerability in Duende IdentityServer, an OpenID Connect and OAuth 2.x framework for ASP.NET Core. This vulnerability allows attackers to craft malicious URLs that certain functions in IdentityServer may incorrectly identify as local and trusted. If such a URL is returned as a redirect, some browsers might follow it to a third-party, untrusted site. Importantly, this vulnerability does **not** permit attackers to gain access to user credentials, authorization codes, access tokens, refresh tokens, or identity tokens. Nevertheless, it can be exploited as part of a phishing attack designed to steal user credentials.
The severity of this vulnerability is rated as medium, with a CVSS score of 4.7. Organizations utilizing the affected versions of Duende IdentityServer should take immediate action to mitigate this risk. The vulnerability affects all versions of IdentityServer prior to 7.0.6, 6.3.10, 6.2.5, 6.1.8, and 6.0.5, which contain the necessary fixes. Moreover, versions 5.1 and earlier of Duende.IdentityServer and all versions of IdentityServer4 are no longer supported and will not receive updates.
Given the potential for phishing attacks, organizations should prioritize patching this vulnerability. If immediate upgrading is not feasible, using `IUrlHelper.IsLocalUrl` from ASP.NET Core is recommended to validate return URLs in user interface code in the IdentityServer host.
Organizations should prioritize patching immediately. The risks associated with this vulnerability emphasize the need for effective remediation strategies to protect user data and maintain trust in the identity management system.
Vulnerability Details
The official CVE description states that this vulnerability allows attackers to craft malicious URLs, which can lead to redirects to untrusted third-party sites. The CVSS score is 4.7, indicating a medium severity level. This vulnerability applies to Duende IdentityServer, specifically affecting its URL validation mechanisms.
The vulnerability was published on July 31, 2024, and is classified under CWE-601. The attack vector for this vulnerability is classified as network-based, with a low attack complexity, no privileges required for exploitation, and user interaction required.
Technical Analysis
The root cause of CVE-2024-39694 lies in the incorrect handling of URLs by certain functions in IdentityServer. The attack vector is network-based, meaning that an attacker must be able to send requests to the affected server. The attack complexity is low, as it does not require any special conditions to be met, and no privileges are required. User interaction is required, as the malicious URL must be followed by the user for the attack to succeed.
The vulnerability has low confidentiality impact, as it does not provide access to sensitive data like user credentials. There is no impact on integrity or availability. Organizations using the affected versions must be aware of the potential for phishing attacks that could exploit this vulnerability.
Risk & Impact Analysis
Risk to organizations includes the potential for phishing attacks that could result in credential theft. The blast radius of this vulnerability could be significant, particularly if the IdentityServer is used for authentication across multiple applications. Organizations should assess the urgency of this issue based on its CVSS score and the possibility of exploitation in the wild.
Given the medium severity rating, organizations should address this vulnerability in their priority patch cycle. Failure to do so could lead to compromised user credentials and potential breaches.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The vulnerable versions of Duende IdentityServer include all versions prior to 7.0.6, 6.3.10, 6.2.5, 6.1.8, and 6.0.5. Versions 5.1 and earlier of Duende.IdentityServer, as well as all versions of IdentityServer4, are no longer supported and will not receive updates.
Mitigation & Remediation
Organizations should ensure they upgrade to patched versions of Duende IdentityServer as soon as possible. If upgrading is not feasible, it is advised to utilize `IUrlHelper.IsLocalUrl` from ASP.NET Core to validate return URLs in user interface code within the IdentityServer host. This validation can help prevent the exploitation of this vulnerability.
For further strategies, organizations can implement security controls such as network monitoring and user education to recognize phishing attempts.
For more information on how to protect your organization, consider reviewing our resources on penetration testing and related security practices.
Detection Guidance
To detect potential exploitations of this vulnerability, organizations should monitor for the following indicators: unexpected redirects to untrusted sites, unusual user behavior following URL interactions, and any anomalies in login attempts.
Log files should be reviewed for any suspicious patterns, and real-time monitoring solutions can be employed to alert security teams of potential phishing attempts.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2024-39694 lies in its representation of the ongoing challenges in URL validation within web frameworks. As attackers become more sophisticated, the need for robust validation mechanisms becomes paramount.
This vulnerability illustrates the importance of not only implementing patches but also conducting thorough code reviews and security assessments to identify similar weaknesses. Security teams should adopt proactive measures to safeguard user data and maintain trust.
For further insights into secure practices, organizations can read about penetration testing methodology and how it can enhance your security posture.
Additionally, exploring our guide on vulnerability management programs can provide strategic insights into developing a comprehensive security framework.
Finally, the trends in vulnerability exposure for 2025 highlight the ever-evolving landscape of threats and the necessity for continuous improvement in security practices.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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