CVE-2021-23984 is a medium severity vulnerability affecting Mozilla products, including Firefox and Thunderbird. This vulnerability allows a malicious extension to open a popup window that lacks an address bar, enabling attackers to spoof web pages. Specifically, the title of the popup, which should not be fully controllable, is manipulated in this case. This exploitation could deceive users into entering their credentials on a fake site. The affected versions are Firefox ESR versions prior to 78.9, Firefox versions prior to 87, and Thunderbird versions prior to 78.9.
With a CVSS score of 6.5, this vulnerability is characterized as having a low attack complexity and requiring user interaction, which means that the attacker must convince the user to engage with the malicious extension. The integrity impact is assessed as high, indicating that the risk to users is significant. Organizations using affected versions of Mozilla products should prioritize patching to mitigate the risk.
As of now, there are no known exploits or publicly available proof of concepts for this vulnerability. However, the potential for exploitation remains concerning due to the nature of the attack vector. Thus, organizations should immediately take steps to update their affected software versions to the latest releases.
The urgency for defenders is high as attackers may leverage this vulnerability to gain unauthorized access to sensitive information. Organizations that delay remediation may expose themselves to credential theft and other security risks.
In conclusion, CVE-2021-23984 highlights the importance of keeping software updated and being vigilant against potential phishing schemes facilitated by malicious extensions.
Vulnerability Details
The official description states that a malicious extension could have opened a popup window lacking an address bar. The title of the popup lacking an address bar should not be fully controllable, but in this situation was. This could have been used to spoof a website and attempt to trick the user into providing credentials. The vulnerability affects Firefox ESR versions prior to 78.9, Firefox versions prior to 87, and Thunderbird versions prior to 78.9.
The CVSS score for this vulnerability is 6.5, classified as medium severity. This score indicates that while the vulnerability is serious, the potential impact is somewhat mitigated by user interaction being required for exploitation.
This vulnerability is classified under CWE-290, which pertains to the authentication issues related to spoofing.
Technical Analysis
The root cause of this vulnerability lies in the handling of popup windows by Mozilla products, where the title can be manipulated by extensions. The attack vector is network-based, requiring no privileges for exploitation, but does necessitate user interaction. The attack complexity is considered low, meaning that an attacker could feasibly exploit this vulnerability with minimal effort.
In terms of impact, the confidentiality impact is none, while the integrity impact is high, as the attacker can effectively manipulate what the user sees in the popup. The availability impact is also none, meaning that the application remains operational but may present security risks to the user.
Risk & Impact Analysis
Organizations face a real-world deployment risk due to this vulnerability, as it can lead to credential theft and potentially broader access to sensitive systems. The blast radius of this vulnerability is significant, given the widespread usage of affected products. The urgency assessment based on the CVSS score highlights the need for immediate action.
As this vulnerability is not currently listed in the KEV catalog, the risk may not be as widely recognized, yet organizations should not overlook it. The low EPSS score indicates a lower likelihood of exploitation, but this should not provide grounds for complacency.
Organizations should address this vulnerability in their priority patch cycle to mitigate risks effectively.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions include Firefox versions prior to 87, Firefox ESR versions prior to 78.9, and Thunderbird versions prior to 78.9. Organizations should ensure they update their installations to mitigate this vulnerability.
Mitigation & Remediation
To mitigate this vulnerability, organizations should update to the latest versions of Firefox and Thunderbird. If patches are not immediately available, consider implementing network controls to restrict the installation of unverified extensions. For additional guidance on security measures, organizations may want to refer to application security assessments and ensure that configurations are hardened against potential exploitation.
Detection Guidance
Organizations should monitor logs for any unusual popup window activity, particularly from unverified extensions. Behavioral anomalies such as unexpected prompts for credentials should be carefully reviewed. Additionally, network signatures can be employed to detect attempts to exploit this vulnerability.
AppSecure Threat Intelligence Insight
CVE-2021-23984 serves as a reminder of the importance of secure extension management. The ability for extensions to manipulate popup behaviors illustrates the need for stringent controls and reviews of installed extensions. Organizations should stay informed about vulnerabilities in third-party components and ensure regular updates.
To enhance overall security posture, organizations may benefit from engaging in red teaming services and adopting best practices in application security. Regular training and awareness for users can also mitigate risks associated with extensions.
For organizations looking to improve their security frameworks, understanding the emerging trends in security vulnerabilities is crucial. Regular engagement with penetration testing methodologies can provide valuable insights into potential weaknesses within their systems.
Additionally, staying abreast of the latest security advisories from Mozilla and other vendors can enhance an organization's readiness to respond to vulnerabilities as they arise.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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