CVE-2016-9202 in Email Security Appliance
Summary
by MITRE
A vulnerability in the web-based management interface of Cisco Email Security Appliance (ESA) Switches could allow an unauthenticated, remote attacker to conduct a persistent cross-site scripting (XSS) attack against a user of the affected interface on an affected device. More Information: CSCvb37346. Known Affected Releases: 9.1.1-036 9.7.1-066.
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Analysis
by VulDB Data Team • 10/05/2022
The vulnerability identified as CVE-2016-9202 resides within the web-based management interface of Cisco Email Security Appliance ESA Switches, representing a critical security flaw that enables unauthenticated remote attackers to execute persistent cross-site scripting attacks. This vulnerability specifically affects devices running software versions 9.1.1-036 and 9.7.1-066, making them susceptible to malicious exploitation without requiring any prior authentication credentials or privileged access. The flaw stems from inadequate input validation and output encoding mechanisms within the web interface, allowing attackers to inject malicious script code that persists across user sessions and interactions with the management portal.
The technical implementation of this vulnerability involves the failure to properly sanitize user-supplied input parameters within the ESA web interface components. When legitimate users interact with the affected management interface, the system processes input data without sufficient validation checks, enabling malicious actors to inject XSS payloads through various interface elements such as form fields, URL parameters, or administrative configuration sections. The persistent nature of this attack means that once the malicious script is injected, it remains active within the device's web interface and executes whenever authorized users access the affected management portal, creating a continuous threat vector.
Operational impact assessment reveals severe consequences for organizations utilizing affected ESA appliances, as this vulnerability compromises the integrity of the management interface and potentially exposes sensitive administrative functions to unauthorized access. The persistent XSS attack capability allows attackers to establish long-term presence within the email security infrastructure, enabling them to monitor administrative activities, manipulate configuration settings, or escalate privileges to gain deeper system access. This vulnerability directly impacts the CIA triad by compromising confidentiality through potential data exfiltration, integrity through configuration manipulation, and availability through potential service disruption. Organizations may face regulatory compliance violations and security audit failures when affected devices remain unpatched, particularly in environments governed by standards such as iso 27001 and pci dss.
Mitigation strategies for CVE-2016-9202 require immediate implementation of the vendor-provided security patches and updates released by Cisco to address the identified XSS vulnerability. Organizations should prioritize patch management processes to ensure all affected ESA appliances receive the necessary firmware updates that correct the input validation and output encoding flaws. Network segmentation and access controls should be implemented to limit administrative access to the ESA management interface, while monitoring systems should be deployed to detect anomalous behavior patterns that may indicate exploitation attempts. Security teams should conduct comprehensive vulnerability assessments to identify all instances of affected hardware and implement additional defensive measures such as web application firewalls and enhanced logging configurations to detect and prevent XSS payload injection attempts. This vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and maps to ATT&CK technique T1059.007 for scripting languages, particularly highlighting the persistent nature of the threat vector that enables ongoing exploitation. Organizations must also consider implementing security awareness training for administrators to recognize potential XSS attack indicators and maintain regular security audits to ensure continued protection against similar vulnerabilities in the email security infrastructure.