A significant security vulnerability, identified as CVE-2025-6709, has been discovered in MongoDB Server versions across the 6.0, 7.0, and 8.0 release branches. This flaw allows unauthenticated attackers to trigger a denial of service (DoS) condition, potentially disrupting database operations and affecting business continuity.
Understanding the Vulnerability
The root cause of this vulnerability lies in improper input validation within MongoDB’s OpenID Connect (OIDC) authentication mechanism. Specifically, the server fails to adequately handle certain date values embedded in JSON payloads during the OIDC authentication process. By exploiting this flaw, attackers can send specially crafted JSON data via the MongoDB shell (mongo), leading to an invariant failure that crashes the server.
This vulnerability is particularly concerning because it can be exploited without any authentication credentials. Attackers with network access to the MongoDB server can initiate the attack, making systems exposed to the internet or accessible through compromised networks especially vulnerable.
Affected Versions and Impact
The vulnerability affects the following MongoDB Server versions:
– MongoDB Server v6.0: Versions prior to 6.0.21
– MongoDB Server v7.0: Versions prior to 7.0.17
– MongoDB Server v8.0: Versions prior to 8.0.5
In versions 7.0 and 8.0, the vulnerability can be exploited pre-authentication, allowing unauthenticated remote attackers to crash the server. In version 6.0, exploitation requires successful authentication, which slightly reduces the risk but still poses a significant threat from authenticated users.
The vulnerability has been assigned a CVSS v3.1 score of 7.5, indicating a high severity level. The primary impact is on availability, as successful exploitation results in a denial of service condition. While confidentiality and integrity are not directly affected, the disruption of database services can have cascading effects on applications and services dependent on MongoDB.
Mitigation Strategies
To protect systems from potential exploitation, it is crucial to implement the following mitigation strategies:
1. Immediate Patching: Upgrade MongoDB Server to the latest stable versions that address this vulnerability:
– MongoDB Server 6.0.21
– MongoDB Server 7.0.17
– MongoDB Server 8.0.5
Applying these updates will remediate the vulnerability and protect the server from potential attacks.
2. Disable OIDC Authentication: If immediate patching is not feasible, consider disabling the OIDC authentication mechanism as a temporary measure. This action will mitigate the specific attack vector associated with this vulnerability. However, be aware that disabling OIDC may impact authentication processes that rely on this mechanism.
3. Network Access Controls: Implement strict network access controls to limit exposure. Ensure that MongoDB servers are not accessible from untrusted networks and restrict access to known, trusted IP addresses.
4. Monitoring and Logging: Enhance monitoring and logging to detect unusual activities, such as unexpected server crashes or unauthorized access attempts. Prompt detection can aid in quick response and mitigation of potential attacks.
Broader Context and Related Vulnerabilities
This vulnerability is part of a series of security issues identified in MongoDB servers over recent years. For instance, CVE-2024-3372 involved improper input validation leading to server crashes, while CVE-2025-3085 pertained to certificate validation flaws that could allow unauthorized access. These recurring vulnerabilities underscore the importance of regular security assessments and prompt application of patches to maintain the integrity and availability of MongoDB deployments.
Conclusion
The discovery of CVE-2025-6709 highlights the critical need for organizations to stay vigilant and proactive in managing database security. By promptly updating to the patched versions of MongoDB Server and implementing robust security practices, organizations can mitigate the risks associated with this vulnerability and ensure the continued reliability of their database systems.
