CVE-2021-21206 is a high-severity vulnerability identified in Google Chrome versions prior to 89.0.4389.128. This vulnerability allows for a use after free condition in Blink, which can be exploited by remote attackers to potentially cause heap corruption via a crafted HTML page. The CVSS score of this vulnerability is 8.8, indicating a high severity level that mandates immediate attention from organizations.
The risk to organizations includes potential unauthorized access and data compromise, as attackers may exploit this vulnerability to execute arbitrary code on affected systems. The exploitation status is confirmed, with the vulnerability included in the Known Exploited Vulnerabilities (KEV) catalog, emphasizing the urgency for defenders to implement necessary patches.
Organizations should prioritize patching immediately. The updates to mitigate this vulnerability are readily available, and applying them is crucial to maintaining the integrity and security of systems using Google Chrome.
Failure to address this vulnerability in a timely manner can lead to significant risks, including data breaches and operational disruptions. Therefore, swift action is essential.
Vulnerability Details
The official description states that this vulnerability allows a remote attacker to potentially exploit heap corruption via a crafted HTML page. The vulnerability falls under the CWE-416 classification, which pertains to use after free issues. The CVSS score of 8.8 reflects the potential impact on confidentiality, integrity, and availability.
The affected product is Google Chrome, specifically versions prior to 89.0.4389.128. The vulnerability was published on April 26, 2021, and last modified on October 24, 2025.
Technical Analysis
The root cause of CVE-2021-21206 is linked to improper memory management in the Blink rendering engine of Google Chrome, leading to a use after free condition. This vulnerability requires user interaction, as the attacker must entice the victim to visit a maliciously crafted webpage. The attack vector is network-based, with low attack complexity and no privileges required to exploit it.
The confidentiality, integrity, and availability impacts are all high, indicating that exploitation could lead to significant data loss or unauthorized access to sensitive information.
Risk & Impact Analysis
Organizations deploying Google Chrome are at a heightened risk due to the potential for exploitation through this vulnerability. The blast radius could extend to any user interacting with affected versions, including users of various operating systems like Fedora. The urgency is further emphasized by the vulnerability's inclusion in the KEV catalog, which indicates that it is being actively exploited.
Given the high severity score, organizations should assess their exposure and prioritize remediation efforts as part of their security strategy. Addressing this vulnerability is crucial to mitigating the risk of unauthorized access and maintaining overall system integrity.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | Yes |
Ransomware Use | No |
Affected Versions
The vulnerability impacts all versions of Google Chrome prior to 89.0.4389.128. Additionally, it affects Fedora 32, 33, and 34 installations that utilize the vulnerable versions of the software.
Mitigation & Remediation
To mitigate the risks associated with CVE-2021-21206, organizations should apply the latest updates from Google Chrome. The recommended action is to upgrade to versions 89.0.4389.128 or later. If immediate patching is not feasible, organizations should implement network controls to restrict access to potentially malicious sites.
Organizations can also consider continuous security testing to identify and remediate similar vulnerabilities proactively. For more information on effective security practices, refer to the penetration testing services available.
Detection Guidance
To detect potential exploitation of CVE-2021-21206, organizations should monitor logs for unusual behavior patterns, including unexpected crashes of the browser or memory-related errors. Additionally, implementing network signatures to flag traffic from known malicious domains can help in identifying attempts to exploit this vulnerability.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-21206 lies in its representation of broader trends in web browser vulnerabilities and the necessity for constant vigilance in security practices. Organizations using Chromium-based browsers must recognize the potential for similar vulnerabilities and the importance of applying updates promptly.
This incident serves as a reminder that even widely used applications can harbor critical security vulnerabilities. Security teams should prioritize the development of a comprehensive vulnerability management program to ensure timely responses to emerging threats.
For further insights into vulnerability management, organizations can refer to the following resources: vulnerability management program design, penetration testing methodology, and security testing best practices to enhance their defensive capabilities.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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