CVE-2023-24459

Vulnerability

Overview

Jenkins BearyChat Plugin 3.0.2 and earlier does not perform a permission check in an unspecified function, allowing attackers with only Overall/Read permission to trigger a connection to a URL of the attacker's choosing [1][2]. This missing permission check means that any user who can read the Jenkins controller can abuse this functionality, bypassing the intended authorization controls.

Exploitation and

Attack Surface

The issue is exposed to any Jenkins user who holds the Overall/Read permission, which is often granted to a broad set of users. No additional privileges are required. An attacker can supply an arbitrary URL (e.g., to a malicious web server) that the plugin will connect to when the vulnerable endpoint is invoked. This may allow the attacker to exfiltrate information (such as Jenkins internal hostname or environment details) via the connection attempt, or to induce the Jenkins controller to interact with external systems without proper validation [1].

Impact

Successfully exploiting this flaw enables an attacker to force the Jenkins controller to initiate an HTTP(S) request to an attacker-specified URL. While the advisory does not detail a direct remote code execution, the SSRF-like behavior can be used for reconnaissance, scanning internal network resources from the Jenkins controller's perspective, or potentially leveraging the connection in further attacks [1][2]. The impact is limited by the fact that the plugin does not return the response content to the attacker directly, but the outbound connection itself can be observed or exploited.

Mitigation

The official Jenkins security advisory released on 2023-01-24 confirms this vulnerability and recommends upgrading to a patched version. As of the advisory, no fix was announced for BearyChat Plugin; users are advised to limit the Overall/Read permission or remove the plugin if not needed [1]. The CVE has a CVSS score of 5.3 (Medium) according to NVD [2], and there is no known evidence of active exploitation in the wild at the time of publication.