CVE-2022-26136 Overview
CVE-2022-26136 is a critical Servlet Filter bypass vulnerability affecting multiple Atlassian products. This flaw allows a remote, unauthenticated attacker to bypass Servlet Filters used by first and third-party applications. The actual impact varies depending on which filters are used by each app and how the filters are implemented, but confirmed consequences include authentication bypass and cross-site scripting (XSS) attacks.
The vulnerability exists across Atlassian's enterprise product suite, making it particularly concerning for organizations that rely on these tools for software development, collaboration, and IT service management. Because the vulnerability allows bypassing security filters without authentication, attackers can potentially gain unauthorized access to sensitive systems and data.
Critical Impact
Unauthenticated remote attackers can bypass Servlet Filters to achieve authentication bypass and cross-site scripting, potentially compromising enterprise collaboration and development infrastructure.
Affected Products
- Atlassian Bamboo (versions before 8.0.9, from 8.1.0 before 8.1.8, and from 8.2.0 before 8.2.4)
- Atlassian Bitbucket (versions before 7.6.16, from 7.7.0 before 7.17.8, from 7.18.0 before 7.19.5, from 7.20.0 before 7.20.2, from 7.21.0 before 7.21.2, and versions 8.0.0 and 8.1.0)
- Atlassian Confluence Server and Data Center (versions before 7.4.17, from 7.5.0 before 7.13.7, from 7.14.0 before 7.14.3, from 7.15.0 before 7.15.2, from 7.16.0 before 7.16.4, from 7.17.0 before 7.17.4, and version 7.21.0)
- Atlassian Crowd (versions before 4.3.8, from 4.4.0 before 4.4.2, and version 5.0.0)
- Atlassian Fisheye and Crucible (versions before 4.8.10)
- Atlassian Jira Server and Data Center (versions before 8.13.22, from 8.14.0 before 8.20.10, and from 8.21.0 before 8.22.4)
- Atlassian Jira Service Management (versions before 4.13.22, from 4.14.0 before 4.20.10, and from 4.21.0 before 4.22.4)
Discovery Timeline
- July 20, 2022 - CVE-2022-26136 published to NVD
- November 21, 2024 - Last updated in NVD database
Technical Details for CVE-2022-26136
Vulnerability Analysis
This vulnerability stems from improper handling of Servlet Filters within Atlassian's Java-based web applications. Servlet Filters are components that intercept HTTP requests and responses to perform security functions such as authentication, authorization, input validation, and output encoding. By bypassing these filters, attackers can circumvent security controls that would normally prevent unauthorized access or malicious input.
The vulnerability is classified under CWE-180 (Incorrect Behavior Order: Validate Before Canonicalize) and CWE-287 (Improper Authentication). The combination of these weaknesses indicates that the filter bypass occurs due to improper request processing order, allowing attackers to craft requests that evade security checks.
Atlassian has noted that while they have addressed the root cause, they have not exhaustively enumerated all potential consequences. This suggests the vulnerability could have additional exploitation scenarios beyond the confirmed authentication bypass and XSS attacks.
Root Cause
The root cause involves incorrect ordering or handling of Servlet Filter execution within the affected Atlassian products. When HTTP requests are processed, the security filters responsible for authentication and input sanitization can be bypassed through specially crafted requests. This allows malicious requests to reach application endpoints without proper security validation.
The vulnerability affects both first-party Atlassian filters and third-party filters installed via marketplace apps or custom development, amplifying the potential attack surface significantly.
Attack Vector
An attacker exploits this vulnerability by sending specially crafted HTTP requests to vulnerable Atlassian instances. The attack vector is network-based and requires no authentication or user interaction, making it highly exploitable.
The exploitation process typically involves:
- Identifying a vulnerable Atlassian product exposed to the network
- Crafting HTTP requests designed to bypass Servlet Filter processing
- Exploiting the bypassed authentication to access restricted functionality
- Alternatively, injecting malicious scripts that bypass XSS filters
Since the specific exploitation mechanism varies based on which filters are bypassed and how they're configured, the actual attack payloads differ across installations. The vulnerability affects the core filter processing mechanism, meaning any security control implemented via Servlet Filters could potentially be circumvented.
Detection Methods for CVE-2022-26136
Indicators of Compromise
- Unusual authentication patterns or access to restricted endpoints without valid session tokens
- Web server logs showing malformed or unusual HTTP requests targeting Atlassian application endpoints
- Evidence of XSS payloads in application logs or user-submitted content
- Unauthorized administrative actions or configuration changes in affected Atlassian products
- Anomalous user account activity or creation of unauthorized accounts
Detection Strategies
- Monitor web application firewall (WAF) logs for requests attempting to bypass authentication endpoints
- Implement anomaly detection for HTTP request patterns that deviate from normal application behavior
- Review Atlassian application access logs for authentication bypass attempts or unauthorized endpoint access
- Deploy endpoint detection solutions to identify post-exploitation activity following successful authentication bypass
Monitoring Recommendations
- Enable detailed access logging on all affected Atlassian products
- Configure alerting for failed and successful authentication events from unexpected sources
- Monitor for new user account creation or privilege escalation activities
- Implement network traffic analysis to detect unusual communication patterns with Atlassian servers
How to Mitigate CVE-2022-26136
Immediate Actions Required
- Identify all Atlassian products in your environment and determine their current versions
- Restrict network access to Atlassian instances to trusted networks and users where possible
- Review access logs for signs of exploitation attempts
- Apply available security patches as the highest priority
- Temporarily disable internet-facing access to vulnerable instances if patching cannot be performed immediately
Patch Information
Atlassian has released security updates that fix the root cause of this vulnerability. Organizations should upgrade to the following minimum versions:
- Bamboo: 8.0.9, 8.1.8, or 8.2.4 (depending on your version branch)
- Bitbucket: 7.6.16, 7.17.8, 7.19.5, 7.20.2, 7.21.2, or later releases after 8.1.0
- Confluence: 7.4.17, 7.13.7, 7.14.3, 7.15.2, 7.16.4, 7.17.4, or later
- Crowd: 4.3.8, 4.4.2, or later releases after 5.0.0
- Fisheye/Crucible: 4.8.10 or later
- Jira: 8.13.22, 8.20.10, or 8.22.4 (depending on your version branch)
- Jira Service Management: 4.13.22, 4.20.10, or 4.22.4 (depending on your version branch)
Refer to the official Atlassian security advisories for your specific product: Atlassian Issue BAM-21795, Atlassian Issue BSERV-13370, Atlassian Issue CONFSERVER-79476, Atlassian Issue CWD-5815, Atlassian Issue FE-7410, Atlassian Issue CRUC-8541, Atlassian Issue JRASERVER-73897, and Atlassian Issue JSDSERVER-11863.
Workarounds
- Implement network-level access controls to restrict access to Atlassian instances from untrusted networks
- Deploy a web application firewall (WAF) with rules to detect and block filter bypass attempts
- Enable additional authentication mechanisms such as multi-factor authentication where supported
- Review and harden third-party app configurations that rely on Servlet Filters for security
# Example: Restrict Atlassian instance access using iptables
# Allow access only from trusted corporate network
iptables -A INPUT -p tcp --dport 8080 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 8080 -j DROP
# For Confluence/Jira behind a reverse proxy, configure access restrictions
# in your nginx or Apache configuration
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
