CVE-2020-24924 in ElkarBackup
Summary
by MITRE
A Persistent Cross-site Scripting vulnerability is found in ElkarBackup v1.3.3, where an attacker can steal the user session cookie using this vulnerability present on Policies >> action >> Name Parameter
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Analysis
by VulDB Data Team • 09/16/2020
This vulnerability represents a critical persistent cross-site scripting flaw in ElkarBackup version 1.3.3 that directly impacts user session security. The vulnerability exists within the administrative interface at the Policies >> action >> Name Parameter path, allowing attackers to inject malicious scripts that persist across user sessions. This type of vulnerability falls under CWE-79 which specifically addresses cross-site scripting conditions where input is not properly validated or sanitized before being rendered in web pages. The attack vector exploits the lack of proper input sanitization in the name parameter handling within the backup policy configuration section, creating a persistent threat that can affect all users who interact with the affected interface.
The operational impact of this vulnerability extends beyond simple script execution as it enables session hijacking and unauthorized access to backup management functionalities. When an attacker successfully injects malicious JavaScript into the name parameter, the script executes in the context of authenticated users' browsers, potentially allowing the attacker to steal session cookies, modify backup configurations, or gain elevated privileges within the backup system. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under T1566 for credential access through social engineering and T1071 for application layer protocol usage. The persistent nature of the XSS means that the malicious script will execute for any user who views the affected policy page, making it particularly dangerous for environments where multiple administrators or users interact with the backup system.
The technical exploitation requires minimal prerequisites as attackers only need to navigate to the vulnerable policies configuration section and inject malicious payloads into the name parameter field. This vulnerability demonstrates poor input validation practices and insufficient output encoding mechanisms in the web application's user interface components. The affected version of ElkarBackup fails to implement proper sanitization of user-supplied input before rendering it in HTML contexts, creating an environment where malicious scripts can be stored and executed repeatedly. Organizations utilizing this backup solution face significant risk of unauthorized access to their backup infrastructure, potentially leading to data loss, system compromise, or unauthorized modification of backup policies and schedules. The vulnerability is particularly concerning because it affects administrative functions that control backup operations, potentially allowing attackers to disrupt backup processes or access sensitive backup data.
Mitigation strategies should focus on immediate input validation and output encoding improvements within the ElkarBackup application. Organizations should implement proper parameter sanitization for all user inputs, particularly those used in HTML rendering contexts, and apply CSP (Content Security Policy) headers to limit script execution. The most effective remediation involves updating to a patched version of ElkarBackup that addresses the XSS vulnerability through proper input validation and output encoding. Additionally, network-level protections such as web application firewalls can provide temporary defense while patches are deployed. Security monitoring should be enhanced to detect unusual parameter submissions in administrative interfaces, and regular security audits should verify that all user inputs are properly sanitized before processing. Organizations should also consider implementing additional authentication controls and session management improvements to reduce the impact of potential session hijacking attempts.