CVE-2021-25215 is classified as a high-severity vulnerability with a CVSS score of 7.5. This vulnerability allows a denial of service (DoS) condition in various versions of BIND, specifically when a vulnerable instance of the named process receives a specific query. The affected versions include BIND 9.0.0 through 9.11.29, 9.12.0 through 9.16.13, and the 9.17 development branch up to version 9.17.11.
The risk to organizations includes potential service disruptions due to the termination of the named process caused by a failed assertion check. This vulnerability impacts all currently maintained BIND 9 branches and can lead to significant operational challenges.
Organizations should prioritize patching immediately. No known exploits have been confirmed at this time, but the potential for exploitation necessitates swift action to mitigate risks.
The vulnerability was published on April 29, 2021, and has been classified as CWE-617, indicating an assertion check failure. Immediate attention to this issue is critical to ensure continued service availability.
As a defensive measure, organizations utilizing affected BIND versions should ensure that they are running the latest patches provided by their respective vendors.
Vulnerability Details
The official description of CVE-2021-25215 states that in the specified BIND versions, when a vulnerable version of named receives a query for a record triggering the flaw, the named process will terminate due to a failed assertion check. This affects all maintained BIND 9 branches, emphasizing the widespread nature of this vulnerability.
The vulnerability is categorized under the high severity level due to its potential impact on availability. The CVSS vector string for this vulnerability is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, which indicates low attack complexity and no privileges or user interaction required for exploitation.
Technical Analysis
The root cause of this vulnerability lies in the handling of specific queries by the named process within BIND. The attack vector is through the network, and the complexity of exploiting this vulnerability is low, as no privileges or user interaction are needed. The main impact of this vulnerability is on availability, as a successful exploitation can lead to service interruption.
Defenders should note that while no public exploit has been confirmed, the availability impact is significant, warranting immediate action.
Risk & Impact Analysis
The real-world deployment risk associated with CVE-2021-25215 is substantial. Organizations using the affected versions of BIND may face service disruptions that could impact critical operations. This vulnerability exemplifies the necessity for continuous monitoring of software updates and vulnerability disclosures, especially for software that is foundational to network operations.
Given the high CVSS score and the potential for denial of service, organizations should assess their exposure and prioritize remediation as part of their security posture.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of BIND include:
1. BIND 9.0.0 to 9.11.29 2. BIND 9.12.0 to 9.16.13 3. BIND 9.17.0 to 9.17.11
Mitigation & Remediation
Organizations should immediately patch their systems to the latest versions of BIND as recommended by the vendor. For those unable to apply patches right away, consider implementing network controls to limit exposure and monitor for unusual queries that could trigger the vulnerability.
For detailed guidance on patching and configuration hardening, organizations may refer to the application security assessment resources available.
Detection Guidance
To detect potential exploitation attempts of CVE-2021-25215, organizations should monitor logs for abnormal behavior associated with the named process.
Indicators include unexpected terminations and unusual query patterns. Implementing effective logging and alerting mechanisms can help in promptly identifying such anomalies.
AppSecure Threat Intelligence Insight
CVE-2021-25215 highlights the importance of maintaining up-to-date software and the potential risks associated with denial of service vulnerabilities. Security teams should ensure robust patch management practices to mitigate such vulnerabilities proactively.
Organizations may also benefit from reviewing their vulnerability management programs to ensure comprehensive coverage against similar risks.
To further enhance security, organizations should consider engaging in penetration testing to identify potential weaknesses before they are exploited.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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