CVE-2023-32996 in SAML Single Sign On Plugin
Summary
by MITRE • 05/16/2023
A missing permission check in Jenkins SAML Single Sign On(SSO) Plugin 2.0.0 and earlier allows attackers with Overall/Read permission to send an HTTP POST request with JSON body containing attacker-specified content, to miniOrange's API for sending emails.
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Analysis
by VulDB Data Team • 01/24/2025
The vulnerability identified as CVE-2023-32996 represents a critical authorization bypass flaw within the Jenkins SAML Single Sign On plugin version 2.0.0 and earlier. This issue stems from a missing permission check that allows unauthenticated or improperly authorized users to exploit the plugin's functionality. The vulnerability specifically affects systems where the miniOrange SAML plugin is installed and configured, creating a pathway for malicious actors to leverage existing read permissions to execute unauthorized actions. The flaw resides in the plugin's handling of HTTP POST requests directed toward miniOrange's external API endpoints, which are typically used for legitimate email notification services within the SAML authentication flow.
The technical implementation of this vulnerability occurs when an attacker with merely Overall/Read permission can construct and send specially crafted HTTP POST requests containing JSON payloads to miniOrange's email sending API. This permission bypass allows the malicious actor to utilize the plugin's legitimate email functionality for unauthorized purposes, potentially enabling spamming, phishing campaigns, or data exfiltration through the email infrastructure. The vulnerability manifests because the plugin fails to validate whether the requesting user has proper authorization to perform email-sending operations, despite the fact that such operations are typically restricted to administrative users. This missing validation creates a direct pathway for privilege escalation through the exploitation of legitimate plugin features.
The operational impact of CVE-2023-32996 extends beyond simple unauthorized email sending capabilities, as it can be leveraged for broader security compromise within Jenkins environments. Attackers can potentially use this vulnerability to send phishing emails that appear to originate from the Jenkins server, enabling social engineering attacks against users. The vulnerability also creates opportunities for spamming activities that could overwhelm email systems or be used to distribute malicious content. Additionally, since the plugin integrates with SAML authentication flows, the attack surface expands to include potential credential harvesting or session manipulation activities that could affect the broader authentication infrastructure. The vulnerability aligns with CWE-863, which addresses "Incorrect Authorization," and represents a clear violation of the principle of least privilege in access control mechanisms.
Organizations utilizing Jenkins SAML plugins should immediately implement mitigations to address this vulnerability, with the most effective solution being the immediate upgrade to plugin versions that have addressed the permission checking flaw. The recommended approach involves verifying the current plugin version and applying the latest security patches from the Jenkins plugin repository, which typically include proper authorization checks and validation of user permissions before allowing email-sending operations. Network segmentation and access controls should be implemented to limit exposure of the Jenkins server to untrusted networks, while monitoring should be enhanced to detect unusual email-sending activities. Security teams should also review existing SAML configurations to ensure that appropriate user roles and permissions are properly enforced, and consider implementing additional logging and alerting mechanisms around plugin-specific API endpoints. This vulnerability demonstrates the critical importance of proper access control validation in authentication and authorization systems, aligning with ATT&CK technique T1566 for social engineering and T1078 for valid accounts, as attackers can exploit legitimate access to perform unauthorized activities.