CVE-2015-0734 in Email Security Appliance
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities on the Cisco Email Security Appliance (ESA) 8.5.6-106 allow remote attackers to inject arbitrary web script or HTML via unspecified parameters in a (1) GET or (2) POST request, aka Bug ID CSCut87743.
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Analysis
by VulDB Data Team • 05/17/2022
The Cisco Email Security Appliance ESA version 8.5.6-106 contains multiple cross-site scripting vulnerabilities that represent a significant security risk for organizations relying on this email protection platform. These vulnerabilities fall under the Common Weakness Enumeration category CWE-79, which specifically addresses cross-site scripting flaws where improper validation of user-supplied input allows malicious scripts to be executed in the context of other users' browsers. The affected system operates as a critical email security gateway, filtering and protecting enterprise email communications from various threats including malware, spam, and phishing attacks.
The technical flaw manifests when the ESA processes GET or POST requests containing malicious input through unspecified parameters within the web interface. Attackers can exploit these vulnerabilities by crafting specially formatted requests that bypass input validation mechanisms, allowing arbitrary web script or HTML code to be injected into the application's response. This injection occurs because the appliance fails to properly sanitize or encode user-supplied data before incorporating it into dynamically generated web pages, creating an environment where malicious payloads can execute in the browser context of authenticated users. The vulnerability affects the web-based management interface of the appliance, making it accessible to remote attackers without requiring local access or authentication to the system.
The operational impact of these XSS vulnerabilities is substantial as they can be leveraged by remote attackers to perform various malicious activities within the compromised environment. An attacker could steal session cookies, allowing them to hijack user sessions and gain unauthorized access to the ESA management interface. Additionally, the vulnerability could enable the execution of malicious scripts that redirect users to phishing sites, modify email filtering rules, or even exfiltrate sensitive configuration data. Since the ESA serves as a central email security component, successful exploitation could potentially compromise the entire email infrastructure of an organization, leading to data breaches, unauthorized email access, or disruption of critical communication channels.
Organizations should implement immediate mitigations including applying the latest security patches released by Cisco to address the identified vulnerabilities. Network segmentation and access controls should be enforced to limit exposure of the ESA management interface to trusted networks only. Input validation and output encoding mechanisms should be strengthened through web application firewall rules that monitor and filter suspicious payloads. Regular security assessments and penetration testing should be conducted to identify additional potential vulnerabilities in the email security infrastructure. The ATT&CK framework categorizes these vulnerabilities under the T1059.007 technique for "Command and Scripting Interpreter: JavaScript' and T1566.001 for 'Phishing: Spearphishing Attachment', highlighting the potential for both automated exploitation and social engineering attacks that could leverage these flaws to compromise email security systems.