CVE-2011-5114 in Barracuda Link Balancer
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in the Authoritative DNS - DNS Zones page in Barracuda Link Balancer 330 Firmware 1.3.2.005 and earlier allow remote attackers to inject arbitrary web script or HTML via the (1) zoneid or (2) scope parameter.
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Analysis
by VulDB Data Team • 01/24/2018
The vulnerability CVE-2011-5114 represents a critical cross-site scripting flaw in the Barracuda Link Balancer 330 device firmware version 1.3.2.005 and earlier releases. This security weakness resides within the Authoritative DNS DNS Zones page functionality, making it particularly dangerous as it affects the core network infrastructure management interface. The vulnerability demonstrates a classic input validation failure where user-supplied parameters are not properly sanitized before being processed and rendered back to the user's browser, creating an avenue for malicious actors to execute arbitrary code within the context of authenticated sessions.
The technical implementation of this vulnerability involves two specific parameter injection points within the DNS management interface. The zoneid and scope parameters serve as entry vectors for malicious payloads, allowing attackers to inject HTML content or JavaScript code that executes in the victim's browser when the affected page is loaded. This flaw directly maps to CWE-79 which defines cross-site scripting as the improper sanitization of input data that is subsequently used in web page generation. The vulnerability is particularly concerning because it affects administrative interfaces that typically require elevated privileges, meaning successful exploitation could provide attackers with access to sensitive network configuration data and potentially enable further attacks within the network infrastructure.
The operational impact of CVE-2011-5114 extends beyond simple data theft or defacement, as it creates a persistent threat vector for network administrators. Attackers could leverage this vulnerability to establish persistent access to the DNS management interface, potentially allowing them to modify DNS records, redirect traffic to malicious destinations, or monitor network communications. This vulnerability aligns with ATT&CK technique T1566 which describes the use of malicious content in web applications to compromise systems, and T1071 which covers application layer protocols including DNS manipulation. The attack surface is particularly broad given that DNS management interfaces often contain critical network configuration information that can be leveraged for lateral movement within corporate networks.
Mitigation strategies for this vulnerability should focus on immediate firmware updates to versions that address the input validation flaws. Organizations should implement network segmentation to isolate critical infrastructure devices and reduce the potential impact of successful exploitation. Additionally, web application firewalls and input validation controls should be deployed to filter malicious payloads before they reach the vulnerable application interface. Regular security assessments of network infrastructure devices should be conducted to identify similar vulnerabilities, as this type of flaw often indicates broader issues with input sanitization practices within the device's web interface. The vulnerability also underscores the importance of maintaining up-to-date firmware and security patches for network appliances, as the affected firmware version represents an outdated and unsupported configuration that leaves systems exposed to known attack vectors.