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CVE-2021-39428: n/a in n/a

Medium
VulnerabilityCVE-2021-39428cvecve-2021-39428n-acwe-79
Published: Thu Dec 15 2022 (12/15/2022, 00:00:00 UTC)
Source: CVE
Vendor/Project: n/a
Product: n/a

Description

Cross Site Scripting (XSS) vulnerability in Users.php in eyoucms 1.5.4 allows remote attackers to run arbitrary code and gain escalated privilege via the filename for edit_users_head_pic.

AI-Powered Analysis

AILast updated: 06/21/2025, 15:07:59 UTC

Technical Analysis

CVE-2021-39428 is a Cross-Site Scripting (XSS) vulnerability identified in the Users.php component of eyoucms version 1.5.4. This vulnerability arises due to insufficient sanitization or validation of the filename parameter used in the edit_users_head_pic functionality. An attacker can exploit this flaw by crafting a malicious filename that, when processed by the vulnerable application, allows the injection and execution of arbitrary JavaScript code within the context of the victim's browser session. The vulnerability requires the attacker to have some level of privileges (PR:L) and user interaction (UI:R), such as convincing a user to click a crafted link or upload a malicious file. The CVSS 3.1 base score is 5.4 (medium severity), reflecting that the attack vector is network-based (AV:N), with low attack complexity (AC:L), but requires privileges and user interaction. The scope is changed (S:C), indicating that the vulnerability can affect resources beyond the initially vulnerable component. The impact affects confidentiality and integrity to a limited extent (C:L, I:L), but does not impact availability (A:N). Exploitation could lead to privilege escalation within the application, potentially allowing an attacker to perform unauthorized actions or access sensitive user data. No public exploits are currently known in the wild, and no official patches or vendor information are provided. The vulnerability is classified under CWE-79, which is the standard classification for XSS issues. Given the lack of vendor and product details, it is assumed that eyoucms is a content management system used for website management, and the affected version is 1.5.4. The vulnerability's exploitation requires some level of authentication and user interaction, limiting its ease of exploitation but still posing a significant risk in environments where the CMS is deployed and users have elevated privileges.

Potential Impact

For European organizations using eyoucms 1.5.4, this vulnerability poses a moderate risk. Successful exploitation could allow attackers to execute arbitrary scripts in the context of authenticated users, potentially leading to session hijacking, unauthorized actions, or privilege escalation within the CMS. This could compromise the confidentiality and integrity of user data and website content. Organizations relying on eyoucms for public-facing websites or internal portals may face reputational damage, data leakage, or unauthorized modifications. Given that the vulnerability requires user interaction and some privileges, the impact is more pronounced in environments where multiple users have elevated access or where social engineering can be leveraged. The lack of a patch increases the risk window, especially for organizations that have not implemented compensating controls. Additionally, if the CMS is used in sectors with strict data protection regulations such as GDPR, exploitation could lead to regulatory non-compliance and associated penalties. The vulnerability does not directly affect availability, so denial of service is unlikely. However, indirect impacts such as website defacement or unauthorized content injection could disrupt business operations or customer trust.

Mitigation Recommendations

1. Immediate mitigation should focus on restricting access to the Users.php edit_users_head_pic functionality to only trusted and necessary users, minimizing the attack surface. 2. Implement strict input validation and sanitization on all filename inputs, ensuring that special characters and script tags are properly escaped or rejected. 3. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in the browser context, mitigating the impact of XSS attacks. 4. Monitor and audit user activities related to profile picture edits or file uploads to detect suspicious behavior. 5. If possible, isolate the CMS environment from critical internal networks to limit lateral movement in case of compromise. 6. Educate users with elevated privileges about the risks of clicking untrusted links or uploading files from unknown sources to reduce the likelihood of social engineering exploitation. 7. Regularly back up CMS data and configurations to enable quick recovery from potential unauthorized changes. 8. Engage with the eyoucms community or vendor to obtain or develop patches addressing this vulnerability. 9. Consider deploying web application firewalls (WAF) with rules tailored to detect and block XSS payloads targeting the affected parameters. 10. Review and tighten authentication and session management controls to reduce the impact of session hijacking attempts.

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Technical Details

Data Version
5.1
Assigner Short Name
mitre
Date Reserved
2021-08-23T00:00:00.000Z
Cisa Enriched
true

Threat ID: 682d984ac4522896dcbf7a48

Added to database: 5/21/2025, 9:09:30 AM

Last enriched: 6/21/2025, 3:07:59 PM

Last updated: 7/26/2025, 5:48:54 AM

Views: 10

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