CVE-2018-11552 in PBX
Summary
by MITRE
There is a reflected XSS vulnerability in AXON PBX 2.02 via the "AXON->Auto-Dialer->Agents->Name" field. The vulnerability exists due to insufficient filtration of user-supplied data. A remote attacker can execute arbitrary HTML and script code in a browser in the context of the vulnerable application.
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Analysis
by VulDB Data Team • 02/11/2020
The reflected cross-site scripting vulnerability identified as CVE-2018-11552 affects AXON PBX version 2.02 and represents a critical security flaw that undermines the application's input validation mechanisms. This vulnerability specifically manifests within the Auto-Dialer module's Agents section where the Name field fails to properly sanitize user-supplied data. The flaw allows malicious actors to inject malicious scripts that execute in the context of the victim's browser session, creating a significant attack surface for remote exploitation. The vulnerability stems from the application's inadequate filtering of input parameters, particularly when processing data submitted through the web interface. This weakness enables attackers to craft malicious payloads that can be stored and subsequently reflected back to users, making it particularly dangerous in multi-user environments where legitimate users might encounter these malicious scripts during normal application interaction.
The technical exploitation of this vulnerability follows standard reflected XSS attack patterns where an attacker crafts a malicious URL containing script code within the Name parameter field. When a victim navigates to this specially crafted URL, the malicious script executes within the victim's browser session, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the victim. The vulnerability directly maps to CWE-79 which defines the weakness of insufficient input validation and improper output encoding in web applications. From an operational perspective, this flaw compromises the integrity of the PBX system's user interface and can lead to unauthorized access to sensitive telephony data, including call logs, user credentials, and communication records. The attack vector requires minimal user interaction beyond visiting a malicious link, making it particularly effective for social engineering campaigns. The reflected nature of the vulnerability means that the malicious payload is not stored on the server but rather reflected back to the user's browser through the application's response, which is why it's classified as a reflected XSS rather than a stored XSS vulnerability.
The impact of this vulnerability extends beyond simple script execution as it can enable more sophisticated attacks within the context of the victim's browser session. Attackers can leverage this flaw to steal session cookies, modify application behavior, redirect users to malicious sites, or even perform administrative actions if the victim has elevated privileges. The vulnerability affects the application's authentication and authorization mechanisms by potentially allowing unauthorized users to execute code that could bypass normal access controls. From a defensive standpoint, this vulnerability highlights the critical importance of implementing proper input validation and output encoding across all web application interfaces. The attack can be classified under ATT&CK technique T1059 which covers command and scripting interpreter usage, specifically targeting web application interfaces for code execution. Organizations should implement comprehensive security measures including web application firewalls, input sanitization, and regular security assessments to prevent exploitation of such vulnerabilities. The remediation approach should focus on implementing proper parameter validation, output encoding, and input sanitization techniques to prevent user-supplied data from being executed as code within the browser context. This vulnerability serves as a reminder of the critical need for security by design principles in telephony and communication systems where user interfaces handle sensitive data and require robust protection against common web application vulnerabilities.