CVE-2019-13643 in EspoCRM
Summary
by MITRE
Stored XSS in EspoCRM before 5.6.4 allows remote attackers to execute malicious JavaScript and inject arbitrary source code into the target pages. The attack begins by storing a new stream message containing an XSS payload. The stored payload can then be triggered by clicking a malicious link on the Notifications page.
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Analysis
by VulDB Data Team • 11/01/2023
The vulnerability CVE-2019-13643 represents a critical stored cross-site scripting flaw in EspoCRM versions prior to 5.6.4, classified under CWE-79 as improper neutralization of input during web page generation. This vulnerability exists within the application's message handling system where user-generated content is not adequately sanitized before being stored and subsequently rendered in web interfaces. The flaw allows remote attackers to inject malicious JavaScript code through the stream messaging functionality, creating a persistent threat that can affect multiple users who view the compromised content. The vulnerability specifically impacts the Notifications page where the stored payload becomes active upon user interaction with malicious links.
The technical implementation of this vulnerability stems from insufficient input validation and output encoding mechanisms within EspoCRM's data persistence layer. When users create stream messages containing malicious payloads, the application fails to properly sanitize these inputs before storing them in the database. The stored content bypasses security filters that should normally prevent execution of script code, allowing attackers to embed JavaScript within legitimate-looking messages. The vulnerability becomes exploitable when victims navigate to the Notifications page where the malicious content is rendered, triggering the stored payload through normal user interaction patterns. This attack vector demonstrates a classic stored XSS scenario where the malicious code executes in the context of the victim's browser session, potentially compromising user credentials or system integrity.
The operational impact of this vulnerability extends beyond simple script execution, creating significant risks for organizations relying on EspoCRM for customer relationship management and business operations. Attackers can leverage this vulnerability to steal session cookies, perform unauthorized actions on behalf of users, or redirect victims to malicious websites. The persistent nature of stored XSS means that once the payload is injected, it can affect multiple users over extended periods without requiring repeated exploitation attempts. This vulnerability particularly threatens administrative accounts and users with elevated privileges, as successful exploitation could lead to complete system compromise. The attack requires minimal user interaction beyond viewing the malicious notification, making it particularly dangerous in enterprise environments where users frequently access notification systems.
Organizations should immediately implement mitigations including updating to EspoCRM version 5.6.4 or later, which contains proper input sanitization and output encoding fixes. Network-level protections such as web application firewalls can provide additional defense-in-depth measures, though they should not be relied upon as the sole protection mechanism. Security teams should conduct thorough audits of all user-generated content systems and implement comprehensive input validation policies. The vulnerability aligns with ATT&CK technique T1566.001 for initial access through malicious links and T1059.007 for command and scripting interpreter usage, making it relevant to broader threat modeling exercises. Regular security testing and code reviews focusing on input validation should be implemented to prevent similar vulnerabilities in custom applications and third-party integrations.