CVE-2021-26076 in JIRA Server
Summary
by MITRE • 04/15/2021
The jira.editor.user.mode cookie set by the Jira Editor Plugin in Jira Server and Data Center before version 8.5.12, from version 8.6.0 before version 8.13.4, and from version 8.14.0 before version 8.15.0 allows remote anonymous attackers who can perform an attacker in the middle attack to learn which mode a user is editing in due to the cookie not being set with a secure attribute if Jira was configured to use https.
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Analysis
by VulDB Data Team • 04/21/2021
The vulnerability CVE-2021-26076 represents a critical security flaw in Atlassian Jira Server and Data Center platforms that affects multiple version ranges including releases before 8.5.12, versions 8.6.0 through 8.13.3, and 8.14.0 through 8.14.9. This issue stems from improper cookie security configuration within the Jira Editor Plugin, specifically concerning the jira.editor.user.mode cookie that tracks user editing states. The vulnerability creates a significant information disclosure risk when Jira instances are configured to use HTTPS protocol, as the cookie lacks the secure attribute that would prevent transmission over unencrypted channels.
The technical flaw manifests when the jira.editor.user.mode cookie is set without the secure flag, allowing attackers who can perform man-in-the-middle attacks to intercept and read the cookie contents. This cookie reveals sensitive information about user editing sessions, including which editing mode a user is currently utilizing within the Jira interface. The vulnerability is particularly dangerous because it operates under the assumption that attackers can position themselves between the user and the Jira server, which is a common attack vector in network environments where traffic interception is possible. This type of vulnerability aligns with CWE-614, which specifically addresses insecure cookies that are not marked as secure, and falls under the broader category of information disclosure vulnerabilities.
The operational impact of this vulnerability extends beyond simple information leakage, as it provides attackers with insights into user behavior patterns and editing sessions within Jira. This information can be leveraged to craft more sophisticated social engineering attacks or to understand the specific workflows and processes that users are engaged in within the platform. The vulnerability creates a persistent risk for organizations using Jira in environments where network security is not fully trusted, potentially exposing sensitive project information or user activities. From an attacker's perspective, this information can be used to target specific user sessions or to understand the timing of user activities, which may be valuable for planning further attacks.
The security implications of this vulnerability are particularly concerning given that it affects multiple version ranges across the Jira Server and Data Center platforms, indicating a widespread exposure across different organizational deployments. Organizations running affected versions should prioritize immediate remediation through patching to version 8.5.12, 8.13.4, or 8.15.0 respectively, depending on their current deployment. Additionally, implementing network-level protections such as strict SSL/TLS configurations and monitoring for suspicious cookie usage patterns can provide additional defense-in-depth measures. The vulnerability also highlights the importance of proper cookie security implementation in web applications, as outlined in various security frameworks including the OWASP Top Ten and NIST cybersecurity guidelines, where insecure cookies represent a persistent threat vector that requires continuous attention and proper configuration management.