CVE-2025-24900 is a high severity vulnerability affecting Concorde, a fork of the federated microblogging platform Misskey. This vulnerability allows MediaProxy authentication to be bypassed due to a lack of CSRF countermeasures and improper settings of cookies. Specifically, in versions prior to 12.25Q1.1, the authentication cookie is missing the SameSite attribute, which permits attackers to bypass MediaProxy authentication and load any image without restrictions under certain circumstances. Furthermore, in versions prior to 12.24Q2.3, this cookie was also used for authenticating the job queue management page (bull-board), enabling further bypass of authentication.Risk to organizations includes significant impacts on availability and integrity. The affected versions are deemed too old to be covered by this advisory, and the maintainers of Concorde strongly recommend not using older versions. In response to this vulnerability, version 12.25Q1.1 has been released, which contains a patch. Organizations are urged to prioritize patching immediately as there are no effective workarounds other than updating.
The CVSS score for this vulnerability is 8.6, indicating a high severity classification. The attack vector is network-based with low complexity and no privileges required, meaning that attackers can exploit this vulnerability without prior authentication. The potential impact on availability is high, while confidentiality and integrity impacts are assessed as none.
With the increasing reliance on web applications, such vulnerabilities underline the necessity for robust security measures and adherence to best practices. Organizations should review their configurations and ensure that security features, such as CSRF countermeasures and proper cookie settings, are implemented effectively.
Vulnerability Details
CVE-2025-24900 affects Concorde, which is a fork of the Misskey microblogging platform. The vulnerability arises from insufficient CSRF protections and incorrect cookie settings related to MediaProxy authentication. Specifically, the cookie used for authentication in versions before 12.25Q1.1 lacks the SameSite attribute. This flaw allows attackers to bypass authentication mechanisms, leading to potential unauthorized access to images and the job queue management page when using older versions.
The vulnerability is classified as CWE-352, which pertains to Cross-Site Request Forgery (CSRF). The CVSS score of 8.6 reflects a high severity, indicating a serious risk that organizations should address promptly.
Technical Analysis
The root cause of CVE-2025-24900 lies in the lack of CSRF protection and improper cookie configuration for MediaProxy authentication. The attack vector is network-based, allowing remote attackers to exploit this vulnerability without needing physical access to the target system. The attack complexity is low, as no special conditions or privileges are required to initiate the attack.
There is no user interaction required to exploit this vulnerability. The confidentiality impact is assessed as none, whereas the integrity impact is also none. However, the availability impact is rated high due to the potential for unauthorized access to media resources, which could disrupt services relying on these images.
Risk & Impact Analysis
Organizations that utilize Concorde should be aware of the real-world risks associated with CVE-2025-24900. The vulnerability poses a significant threat to availability and could lead to unauthorized access to images and the job queue management system. The blast radius for this vulnerability can extend to all users of the affected versions, making it essential for organizations to take immediate action.
Given the CVSS score of 8.6, organizations should prioritize patching immediately. The vulnerability's high availability impact necessitates swift remediation to mitigate potential disruptions and preserve the integrity of services dependent on MediaProxy.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions include all versions prior to 12.25Q1.1. Organizations are advised to update to this version or later to mitigate the risk associated with this vulnerability.
Mitigation & Remediation
To remediate CVE-2025-24900, organizations should upgrade to version 12.25Q1.1 or later. This version includes the necessary patch to address the vulnerability. As there are no effective workarounds available, updating is the only solution to mitigate the risk.Organizations should also consider implementing additional security measures, such as monitoring for unauthorized access attempts and ensuring that CSRF protections are in place for all web applications.
Detection Guidance
Organizations should monitor logs for indicators of unauthorized access to MediaProxy resources and the job queue management page. Behavioral anomalies and unusual access patterns may signify exploitation attempts.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2025-24900 highlights the critical need for developers to implement robust security configurations from the outset. This vulnerability represents a trend toward exploitation of inadequate cookie protections and CSRF vulnerabilities in web applications.Security teams should take this as a lesson to regularly assess their applications against common vulnerabilities and ensure that security best practices are followed during development. Organizations can benefit from adopting a proactive approach to security, such as regular penetration testing and vulnerability assessments.
For more insights on how to improve your security posture, consider reviewing our penetration testing services and other resources.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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