CVE-2025-41355 describes a reflected Cross-Site Scripting (XSS) vulnerability in Anon Proxy Server version 0.104. This vulnerability allows an attacker to execute JavaScript code in the victim's browser by sending a malicious URL. The potential impact includes the theft of sensitive user data, such as session cookies, or actions performed on behalf of the user. It specifically affects the 'port' and 'proxyPort' parameters in the '/anon.php' endpoint.
With a CVSS score of 5.1, this vulnerability is classified as medium severity. Although the attack complexity is low, it requires user interaction, meaning victims must click a malicious link for exploitation to occur. As a result, the risk to organizations includes potential data breaches, unauthorized access, and a compromised user experience. Organizations should prioritize patching immediately.
Currently, there are no known exploits associated with this vulnerability, and it is not listed in the Known Exploited Vulnerabilities (KEV) catalog. However, the medium exploitability factor indicates that organizations must remain vigilant and prepared for potential attacks.
Given the nature of this vulnerability, organizations using Anon Proxy Server should address this issue in their priority patch cycle. Implementing security measures such as web application firewalls and regular security assessments can help mitigate risks associated with XSS vulnerabilities.
Vulnerability Details
The reflected Cross-Site Scripting (XSS) vulnerability in Anon Proxy Server allows attackers to inject malicious scripts into web pages viewed by users. The CVE was published on March 31, 2026, and has been assigned a CVSS score of 5.1, indicating a medium severity level. The attack vector is classified as network-based, and the attack complexity is low, requiring no privileges.
This vulnerability is categorized under CWE-79, which refers to improper neutralization of input during web page generation. The specific affected version is Anon Proxy Server v0.104.
Technical Analysis
The root cause of this vulnerability lies in the improper handling of user input within the Anon Proxy Server. By manipulating the 'port' and 'proxyPort' parameters, an attacker can craft a URL that executes arbitrary JavaScript in the victim's browser. The attack vector is primarily network-based, as the attacker must send the malicious link to the target. The attack complexity is low, as it requires no special permissions or advanced techniques.
User interaction is required to trigger the exploit, as the victim must click the malicious link. The confidentiality impact is categorized as low, with the potential for session cookies and other sensitive user data being exfiltrated. The integrity impact is also low, as it primarily affects the user's session state rather than altering server-side data.
Risk & Impact Analysis
The real-world risk associated with CVE-2025-41355 is significant, as it allows for the potential theft of sensitive user information and unauthorized actions performed in the context of the victim's session. Organizations should recognize that XSS vulnerabilities can lead to broader breaches if exploited, as attackers may gain further access to internal resources.
The urgency assessment based on the CVSS score indicates that while this vulnerability is not critical, it should be addressed promptly to prevent potential exploitation. Organizations must incorporate this vulnerability into their risk management frameworks and prioritize remediation based on their specific threat landscape.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The vulnerable product is Anon Proxy Server v0.104. All versions prior to vendor patch are affected. Organizations are advised to upgrade to the latest version to mitigate this vulnerability.
Mitigation & Remediation
To remediate this vulnerability, organizations should apply the latest updates provided by the vendor for Anon Proxy Server. In cases where a patch is not immediately available, implementing web application firewalls can help filter out malicious requests. Regular security assessments and penetration testing can also help identify and address potential vulnerabilities within web applications.
Organizations should validate remediation through penetration testing to identify any remaining weaknesses.
Detection Guidance
To detect exploitation attempts of this vulnerability, organizations should monitor for unusual user behavior, such as unexpected redirects or unusual parameters being passed in URLs. Additionally, logging and analyzing requests to the '/anon.php' endpoint can help identify potential exploitation.
AppSecure Threat Intelligence Insight
CVE-2025-41355 highlights the ongoing issue of XSS vulnerabilities in web applications, which can lead to significant breaches if not addressed promptly. Organizations should prioritize implementing secure coding practices and regularly train developers on potential threats. For further insights into application security, consider reviewing our resources on vulnerability management and penetration testing methodology to enhance your organization's security posture.
Lastly, reviewing our blog on API security testing can provide additional strategies for securing web applications.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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