CVE-2025-41357 is a reflected Cross-Site Scripting (XSS) vulnerability present in Anon Proxy Server v0.104. This vulnerability allows an attacker to execute JavaScript code in the victim's browser by sending him/her a malicious URL. As a result, attackers may leverage this vulnerability to steal sensitive user data, such as session cookies, or to perform actions on behalf of the user. The flaw specifically affects the 'host' parameter in the '/diagdns.php' endpoint.
With a CVSS score of 5.1, this vulnerability is categorized as medium severity. Organizations should prioritize patching this issue to mitigate potential threats. The vulnerability's nature and the ease with which it can be exploited raise significant concerns for the affected user base.
Risk to organizations includes the unauthorized access to sensitive information, which could lead to further exploitation of user accounts. As the exploitability of this vulnerability is classified as medium, organizations should address it in their priority patch cycle.
Currently, there is no known public proof of concept (PoC) or active exploitation reported in the wild. However, the nature of XSS vulnerabilities means that they can often be exploited without prior notice, making it essential for affected systems to be patched promptly.
Vulnerability Details
The official CVE description states that this vulnerability allows attackers to perform XSS attacks by manipulating the 'host' parameter in the '/diagdns.php' endpoint of Anon Proxy Server v0.104. The vulnerability is classified under CWE-79, which relates to improper neutralization of input during web page generation ('XSS').
The vulnerability was published on March 31, 2026. The CVSS version 4.0 score indicates a network attack vector with low complexity and no privileges required for exploitation. User interaction is required, which implies that the victim must click on a malicious link for the attack to be successful.
Technical Analysis
The root cause of this vulnerability lies in the failure to properly validate and sanitize user inputs in the 'host' parameter. Attackers can craft malicious URLs that execute arbitrary JavaScript in the context of the victim's browser session, allowing them to steal cookies or perform actions on behalf of users.
The attack vector for this vulnerability is network-based, meaning an attacker can exploit it remotely without physical access to the victim's machine. The attack complexity is rated as low, indicating that the exploits can be easily executed with minimal user interaction required.
Since the attack requires user interaction to click on the malicious link, the impact on confidentiality is low, as the attack does not compromise the integrity or availability of the system. However, the potential to compromise user sessions poses significant risks.
Risk & Impact Analysis
The real-world deployment risk associated with CVE-2025-41357 is significant, as it may allow attackers to gain unauthorized access to user accounts and sensitive information. This could lead to credential theft, identity theft, or unauthorized actions performed by the attacker in the victim's name.
Organizations should consider the potential blast radius of this vulnerability, as it can impact any user who interacts with the vulnerable application. The urgency for remediation is underscored by the ease of exploitation and the potential for widespread impact, especially if attackers leverage this vulnerability in phishing campaigns.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The only affected version identified is Anon Proxy Server v0.104. Organizations running this version should prioritize remediation efforts. If version information is missing, it is advisable to assume that all versions prior to the vendor's patch are affected.
Mitigation & Remediation
Organizations should prioritize patching Anon Proxy Server to the latest version provided by the vendor to address this vulnerability. If an immediate update is not feasible, consider implementing input validation and sanitization on user inputs to mitigate the risk of XSS attacks.
For ongoing security, organizations should engage in penetration testing to frequently assess for vulnerabilities and ensure robust security measures are in place.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor logs for indicators of XSS attacks, such as unexpected JavaScript execution or unusual parameters in the URL. Behavioral anomalies in user sessions should also be flagged for investigation.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2025-41357 highlights the ongoing challenges posed by XSS vulnerabilities. As attackers continue to exploit these vulnerabilities, organizations must remain vigilant and proactive in their security strategies.
This vulnerability reflects a broader trend in web application security, emphasizing the importance of input validation and user data protection. Security teams should regularly review their security posture and implement best practices to mitigate such vulnerabilities.
For additional guidance, security teams can refer to resources on web application penetration testing, API penetration testing, and penetration testing methodology for comprehensive security assessments.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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