CVE-2019-20901 in JIRA Server
Summary
by MITRE
The login.jsp resource in Jira before version 8.5.2, and from version 8.6.0 before version 8.6.1 allows remote attackers to redirect users to a different website which they may use as part of performing a phishing attack via an open redirect in the os_destination parameter.
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Analysis
by VulDB Data Team • 07/14/2020
The vulnerability identified as CVE-2019-20901 represents a critical open redirect flaw in Atlassian Jira's login interface, specifically affecting versions prior to 8.5.2 and versions 8.6.0 through 8.6.0. This security weakness resides in the login.jsp resource where the os_destination parameter fails to properly validate user input, creating a pathway for malicious actors to exploit the authentication flow. The flaw allows remote attackers to manipulate the redirect behavior during the login process, potentially enabling them to direct users to attacker-controlled domains that closely resemble legitimate Jira interfaces.
The technical implementation of this vulnerability stems from insufficient validation of the os_destination parameter within the Jira authentication mechanism. When users attempt to log into Jira, the system processes the os_destination parameter to determine where to redirect users after successful authentication. However, the application does not adequately sanitize or verify the input provided in this parameter, allowing attackers to supply malicious URLs that will be processed as legitimate redirect destinations. This creates a dangerous scenario where legitimate users may be unknowingly redirected to phishing sites designed to capture credentials or other sensitive information.
The operational impact of this vulnerability extends beyond simple redirection, as it enables sophisticated social engineering attacks that can bypass user security awareness. Attackers can craft deceptive URLs that appear legitimate within the context of Jira's login process, making it difficult for users to distinguish between authentic and malicious redirects. The vulnerability particularly affects organizations that rely heavily on Jira for project management and collaboration, as successful exploitation could result in credential theft, unauthorized access to sensitive project data, and potential lateral movement within the compromised network. This threat is especially concerning given that Jira is widely used across enterprise environments, making it an attractive target for threat actors seeking to establish persistent access.
Organizations should prioritize immediate remediation by upgrading to Jira version 8.5.2 or 8.6.1, which contain patches addressing this specific vulnerability. The fix implemented by Atlassian involves strengthening input validation for the os_destination parameter, ensuring that only URLs from trusted domains are accepted for redirection. Security teams should also implement additional monitoring of authentication logs to detect unusual redirect patterns that might indicate exploitation attempts. From a defensive perspective, this vulnerability aligns with CWE-601 Open Redirect vulnerability classification and maps to ATT&CK technique T1566.001 Phishing, as it enables attackers to create convincing phishing campaigns that leverage the legitimate Jira authentication flow to deceive users. Organizations should consider implementing web application firewalls and network-level controls to monitor and block suspicious redirect patterns, while also conducting security awareness training to help users recognize potential phishing attempts that exploit such vulnerabilities.