CVE-2021-21080 in Connect
Summary
by MITRE • 03/13/2021
Adobe Connect version 11.0.7 (and earlier) is affected by a reflected Cross-Site Scripting (XSS) vulnerability. An attacker could exploit this vulnerability to inject malicious JavaScript content that may be executed within the context of the victim's browser when they browse to the page containing the vulnerable field.
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Analysis
by VulDB Data Team • 04/01/2021
Adobe Connect version 11.0.7 and earlier implementations contain a reflected cross-site scripting vulnerability that represents a critical security risk to organizations relying on this collaborative platform. This vulnerability falls under CWE-79 which specifically addresses improper neutralization of input during web page generation, making it a prime target for attackers seeking to compromise user sessions and execute malicious code within the browser context of authenticated users. The flaw occurs when the application fails to properly sanitize user-supplied input parameters that are subsequently reflected back in HTTP responses without adequate encoding or validation mechanisms.
The technical exploitation of this vulnerability requires an attacker to craft malicious URLs containing specially crafted script payloads that are then reflected back to the victim's browser when they navigate to the compromised page. This reflected XSS attack vector allows threat actors to inject malicious JavaScript code that executes within the security context of the victim's browser session, potentially enabling session hijacking, credential theft, or redirection to malicious sites. The vulnerability is particularly dangerous because it affects the core functionality of the Adobe Connect platform where users frequently interact with web-based collaborative features, making legitimate user interactions the attack surface for malicious payloads.
The operational impact of this vulnerability extends beyond simple script execution as it can lead to complete compromise of user sessions and potential lateral movement within organizational networks. Attackers can leverage this vulnerability to steal session cookies, capture user credentials, or redirect victims to phishing sites that appear legitimate to the end user. The reflected nature of this XSS vulnerability means that attackers do not need to persist malicious code on the server itself, instead relying on the victim's browser to execute the malicious payload from a crafted URL. This characteristic aligns with ATT&CK technique T1566.001 which describes social engineering through spearphishing with links, making this vulnerability particularly effective when combined with phishing campaigns targeting Adobe Connect users.
Organizations should immediately implement multiple layers of defense to mitigate this vulnerability, beginning with the urgent application of Adobe's security patches released for this specific flaw. Network-based mitigations including web application firewalls and input validation rules can provide temporary protection while patches are deployed. Security teams should also implement strict content security policy headers to prevent execution of unauthorized scripts and monitor for suspicious URL patterns that may indicate exploitation attempts. Regular security awareness training for users can help reduce the risk of successful phishing campaigns that leverage this vulnerability, while comprehensive logging and monitoring of user activities within Adobe Connect environments can aid in early detection of exploitation attempts. The vulnerability demonstrates the critical importance of maintaining up-to-date security patches and implementing proper input validation controls across all web applications to prevent reflected XSS attacks that can compromise entire user sessions and organizational security postures.