CVE-2022-36074 in Server
Summary
by MITRE • 09/16/2022
Nextcloud server is an open source personal cloud product. Affected versions of this package are vulnerable to Information Exposure which fails to strip the Authorization header on HTTP downgrade. This can lead to account access exposure and compromise. It is recommended that the Nextcloud Server is upgraded to 23.0.7 or 24.0.3. It is recommended that the Nextcloud Enterprise Server is upgraded to 22.2.11, 23.0.7 or 24.0.3. There are no known workarounds for this issue.
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Analysis
by VulDB Data Team • 10/18/2022
The vulnerability identified as CVE-2022-36074 affects Nextcloud server versions prior to 23.0.7 and 24.0.3, representing a critical information exposure flaw that undermines the security of user authentication mechanisms. This vulnerability specifically targets the HTTP downgrade process where the system fails to properly strip the Authorization header from requests, creating a significant security gap that can be exploited by malicious actors. The flaw exists in the server's handling of HTTP protocol transitions, where authentication credentials remain accessible even when requests are redirected from secure HTTPS to insecure HTTP connections. This represents a fundamental failure in security boundary enforcement and credential protection mechanisms that directly violates security best practices.
The technical implementation of this vulnerability stems from inadequate header sanitization during HTTP protocol transitions, where the Authorization header containing user authentication tokens is not properly removed or obscured when requests are downgraded from encrypted to unencrypted connections. This behavior creates an attack surface where sensitive authentication information can be intercepted and potentially reused by attackers who have access to the network traffic or can manipulate the HTTP downgrade process. The vulnerability aligns with CWE-200, which addresses improper exposure of sensitive information, and specifically demonstrates weaknesses in authentication and session management. From an operational perspective, this flaw can be exploited through man-in-the-middle attacks or network interception scenarios where attackers can observe the downgraded traffic and extract authentication credentials.
The impact of this vulnerability extends beyond simple credential exposure, as successful exploitation can lead to complete account compromise and unauthorized access to user data stored within the Nextcloud environment. Attackers who successfully exploit this vulnerability can gain access to sensitive documents, personal information, and potentially escalate their privileges within the cloud storage system. This represents a significant risk to organizations relying on Nextcloud for personal cloud storage solutions, as the exposure of authentication headers during HTTP downgrade processes can result in unauthorized data access and potential data breaches. The vulnerability also aligns with ATT&CK technique T1566, which covers credential harvesting through network sniffing and interception attacks.
Organizations using affected Nextcloud server versions must implement immediate remediation measures by upgrading to the recommended versions 23.0.7 or 24.0.3 for the community edition, and 22.2.11, 23.0.7, or 24.0.3 for enterprise editions. These upgrades contain patches that properly handle HTTP header sanitization during protocol transitions and ensure that authentication credentials are not exposed during downgraded connections. Security administrators should also consider implementing additional network security controls such as enforcing HTTPS-only connections, implementing proper certificate validation, and monitoring for unusual HTTP downgrade patterns. The lack of known workarounds for this issue emphasizes the critical nature of applying the vendor-provided patches promptly, as manual mitigation approaches are not feasible due to the fundamental nature of the header sanitization failure within the application's core HTTP handling mechanisms.