CVE-2021-29469 affects the redis.js Node.js Redis client, specifically versions prior to 3.1.1. The vulnerability arises when a client is in monitoring mode, where the regex used to detect monitor messages can cause exponential backtracking on certain strings. This behavior can lead to a denial of service (DoS) condition, making the application unresponsive.
This issue has a CVSS score of 5.3, categorizing it as medium severity. Its high availability impact means that organizations could experience significant service disruption if exploited. Although the attack complexity is rated as high, the risk remains notable as it pertains to the application’s stability.
Organizations utilizing the redis.js client should be aware that the issue is patched in version 3.1.1, and immediate action should be taken to upgrade to this version. Prompt remediation is crucial to prevent potential service interruptions.
Currently, there are no public exploits reported for this vulnerability, which means that while the risk is present, there are no known tools or methods available for attackers to exploit it at this time. Nonetheless, organizations should not delay their patching efforts.
Vulnerability Details
The official CVE description states: "Node-redis is a Node.js Redis client. Before version 3.1.1, when a client is in monitoring mode, the regex begin used to detect monitor messages could cause exponential backtracking on some strings. This issue could lead to a denial of service. The issue is patched in version 3.1.1."
The vulnerability is classified under CWE-400, indicating it relates to uncontrolled resource consumption. The CVSS score given by the NVD is 7.5, categorized as high severity, but the security advisory from GitHub lists it as medium with a score of 5.3. This discrepancy arises from differences in the assessment criteria used by the respective organizations.
This vulnerability is applicable to all versions prior to the vendor patch. It is crucial for users of redis.js to ensure they are operating on version 3.1.1 or later to mitigate risks associated with this vulnerability.
Technical Analysis
The root cause of CVE-2021-29469 lies within the regex handling during monitoring mode. When subjected to specific input patterns, the regex may enter a state of exponential backtracking, consuming increasing amounts of CPU resources and eventually leading to a denial of service condition.
The attack vector is network-based, meaning an attacker would need to send specific requests to the affected service. The attack complexity is rated as high, indicating that successfully triggering this vulnerability requires specific conditions and knowledge of the regex patterns used.
No user interaction is required for the attack to succeed, and the impact on availability is significant. Given the nature of the vulnerability, both confidentiality and integrity are not affected, as the attack focuses solely on exhausting resources.
Risk & Impact Analysis
The potential impact of this vulnerability on organizations is substantial. A successful exploit could result in significant downtime, affecting service availability and user satisfaction. This could ultimately lead to financial losses and damage to the organization's reputation.
Given the CVSS score of 7.5, organizations should address this vulnerability in their priority patch cycle. The fact that it is currently not actively exploited does not diminish its potential for impact, as denial of service can severely disrupt operations.
Organizations should prioritize patching immediately. The blast radius can extend to any applications relying on the redis.js client for Redis operations, amplifying the need for prompt remediation.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of redis.js are all versions prior to 3.1.1. Organizations using these versions should upgrade to the patched version to remediate the vulnerability.
Mitigation & Remediation
To mitigate this vulnerability, organizations should upgrade to redis.js version 3.1.1 or later. If for any reason, immediate patching is not feasible, consider implementing network controls to limit exposure to affected Redis services.
For further guidance on security testing, organizations may refer to penetration testing to ensure no similar vulnerabilities are present.
Detection Guidance
Monitoring for unusual CPU usage patterns may indicate exploitation attempts. Logging of Redis commands could reveal abnormal behavior that warrants further investigation.
AppSecure Threat Intelligence Insight
CVE-2021-29469 highlights the importance of robust input validation and regex handling in application development. This incident serves as a reminder to security teams to continuously evaluate their code for similar vulnerabilities.
Organizations should also consider implementing comprehensive security testing practices, such as penetration testing methodology, to identify weaknesses before they can be exploited.
With the increasing number of vulnerabilities being discovered, it is critical to maintain a proactive security posture. Regular updates and security assessments are essential to protect against potential threats.
For organizations utilizing cloud services, understanding how vulnerabilities like CVE-2021-29469 can impact their infrastructure is crucial. Security assessments specific to cloud environments, including cloud security testing, should be integrated into the overall security strategy.
Known Exploitation Timeline
This vulnerability has not been listed in the KEV catalog, indicating no known exploitation is currently identified.
EPSS Risk Context
The EPSS score for this vulnerability is 0.00926, placing it in the 76th percentile. This suggests a relatively low probability of exploitation, but organizations should remain vigilant.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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