CVE-2021-27465 in Rosemount X-STREAM Gas Analyzer
Summary
by MITRE • 05/21/2021
A vulnerability has been found in multiple revisions of Emerson Rosemount X-STREAM Gas Analyzer. The affected applications do not validate webpage input, which could allow an attacker to inject arbitrary HTML code into a webpage. This would allow an attacker to modify the page and display incorrect or undesirable data.
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Analysis
by VulDB Data Team • 05/23/2021
The vulnerability identified as CVE-2021-27465 affects Emerson Rosemount X-STREAM Gas Analyzer systems across multiple software revisions, representing a critical security flaw that undermines the integrity of industrial control interfaces. This weakness resides in the web application layer of the gas analyzer software, where input validation mechanisms have been inadequately implemented or completely omitted. The affected system operates within industrial environments where accurate data representation is paramount for operational safety and regulatory compliance, making this vulnerability particularly concerning for critical infrastructure sectors.
The technical flaw manifests as a classic cross-site scripting vulnerability, specifically categorized under CWE-79 which defines improper neutralization of input during web page generation. The analyzer applications fail to properly sanitize user inputs received through web interfaces, allowing malicious actors to inject HTML code that executes within the context of other users' browsers. This injection occurs when the system processes user-supplied data without adequate validation or encoding, creating an environment where attacker-controlled content can be seamlessly integrated into legitimate web pages. The vulnerability exists at the application logic level where input handling routines do not distinguish between legitimate user data and potentially malicious code fragments.
The operational impact of this vulnerability extends beyond simple data manipulation, as it fundamentally compromises the trustworthiness of the analyzer's user interface and the data it presents. Attackers could potentially redirect users to malicious websites, steal session cookies, or inject content that could mislead operators into making incorrect decisions based on falsified data readings. In industrial settings where gas analysis data directly influences process control, safety systems, and regulatory reporting, the ability to corrupt displayed information could lead to operational errors, safety hazards, or compliance violations. The vulnerability also enables potential privilege escalation attacks where malicious code could access system resources beyond what normal user access should permit, particularly when the web interface provides administrative functions.
Mitigation strategies for CVE-2021-27465 should prioritize immediate implementation of input validation and output encoding mechanisms across all web application components of the affected Rosemount systems. Organizations must implement comprehensive sanitization of all user inputs through proper encoding techniques such as HTML entity encoding, and establish robust input validation routines that reject suspicious patterns or malformed data. Security patches should be applied immediately to all affected software versions, with network segmentation and access controls implemented to limit exposure. The ATT&CK framework categorizes this vulnerability under T1566 for Phishing and T1059 for Command and Scripting Interpreter, indicating that defenders should monitor for suspicious web traffic patterns and implement web application firewalls to detect and block malicious input attempts. Additionally, regular security assessments and penetration testing should be conducted to identify similar validation gaps in industrial control system interfaces, as this vulnerability represents a common weakness in OT environments where security considerations may be secondary to operational functionality.