CVE-2017-20199 in buttercup-browser-extension
Summary
by MITRE • 08/16/2025
A vulnerability was found in Buttercup buttercup-browser-extension up to 0.14.2. Affected by this vulnerability is an unknown functionality. The manipulation leads to improper access controls. The attack can be launched remotely. The complexity of an attack is rather high. The exploitation appears to be difficult. The exploit has been disclosed to the public and may be used. Upgrading to version 1.0.1 is able to address this issue. The identifier of the patch is 89. It is recommended to upgrade the affected component. This vulnerability only affects products that are no longer supported by the maintainer.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 08/27/2025
The vulnerability identified as CVE-2017-20199 affects the buttercup-browser-extension browser extension version 0.14.2 and earlier, representing a critical access control flaw that compromises the security of affected systems. This issue stems from improper access controls within an unknown functionality of the extension, creating a pathway for unauthorized access that could potentially lead to data exposure or manipulation. The vulnerability's remote exploitability means that attackers can target users without requiring physical access to their systems, making it particularly dangerous in widespread deployment scenarios. The high attack complexity and difficult exploitation requirements suggest that while the vulnerability exists, it may require specialized knowledge or conditions to successfully compromise systems, though the public disclosure of the exploit increases the likelihood of its adoption by threat actors.
The technical nature of this vulnerability aligns with CWE-284, which addresses improper access control issues in software systems, where inadequate privilege management allows unauthorized users to access restricted resources or perform unauthorized operations. The attack vector being remote indicates that the flaw likely exists in network-facing components or communication protocols within the browser extension, potentially through insecure API endpoints or improper authentication mechanisms. The complexity involved in exploitation suggests that attackers may need to overcome additional security measures or require specific conditions to successfully leverage the vulnerability, though the public availability of the exploit undermines this protection. This weakness in access control represents a fundamental security failure that could enable attackers to bypass intended security boundaries within the browser extension's functionality.
The operational impact of this vulnerability extends beyond simple data theft, potentially allowing attackers to manipulate stored credentials, access sensitive user information, or perform unauthorized actions within the browser environment. The fact that this affects a browser extension means that the attack surface includes all web browsing activities, potentially exposing users to credential theft, session hijacking, or other browser-based attacks. The vulnerability's impact is particularly concerning given that it affects a security tool designed to protect user data, creating a paradoxical situation where the protective mechanism itself becomes a security risk. The issue's designation as affecting only unsupported products suggests that the extension may have reached end-of-life status, leaving users without official security updates or patches to address the vulnerability.
The recommended mitigation strategy involves upgrading to version 1.0.1 of the buttercup-browser-extension, which contains the necessary patch addressing the improper access control vulnerability. This upgrade represents a standard remediation approach for software vulnerabilities, where the vendor has developed a fix that resolves the underlying security flaw. The patch identifier 89 provides a reference point for tracking the specific changes implemented to address the issue, though users should verify that the upgrade properly resolves the vulnerability before considering it fully mitigated. Organizations and individuals using the affected extension should prioritize this upgrade immediately, as the public disclosure of the exploit increases the risk of active exploitation attempts. The vulnerability's nature as a remote access control flaw means that users should also consider additional security measures such as monitoring for suspicious browser activity, reviewing stored credentials, and ensuring that browser extensions are regularly updated to maintain security posture.
The broader implications of this vulnerability highlight the importance of maintaining current security software and the risks associated with using unsupported products. Software that reaches end-of-life status often becomes increasingly vulnerable to exploitation as security researchers and attackers focus their efforts on supported platforms, leaving legacy systems exposed to known vulnerabilities. This case demonstrates how even security-focused tools can contain critical flaws that undermine their protective capabilities, emphasizing the need for comprehensive security testing and regular updates across all software components. The vulnerability also underscores the importance of proper access control implementation in browser extensions, where the privileged position these tools hold in user environments makes them attractive targets for attackers seeking to escalate privileges or gain persistent access to systems.