CVE-2017-16613 in Swauth
Summary
by MITRE
An issue was discovered in middleware.py in OpenStack Swauth through 1.2.0 when used with OpenStack Swift through 2.15.1. The Swift object store and proxy server are saving (unhashed) tokens retrieved from the Swauth middleware authentication mechanism to a log file as part of a GET URI. This allows attackers to bypass authentication by inserting a token into an X-Auth-Token header of a new request. NOTE: github.com/openstack/swauth URLs do not mean that Swauth is maintained by an official OpenStack project team.
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Analysis
by VulDB Data Team • 01/11/2023
The vulnerability CVE-2017-16613 represents a critical authentication bypass flaw in OpenStack Swauth middleware version 1.2.0 and earlier, when integrated with OpenStack Swift versions 2.15.1 and earlier. This issue stems from improper handling of authentication tokens within the middleware component, specifically in the middleware.py file where unhashed authentication tokens are being logged to file system output as part of GET URI parameters. The flaw creates a significant security gap in cloud infrastructure deployments that rely on this authentication mechanism, as it exposes sensitive authentication credentials in plaintext format within log files accessible to unauthorized parties.
The technical implementation of this vulnerability involves the Swauth middleware's interaction with Swift's object store and proxy server components during authentication processes. When users authenticate through the Swauth system, the middleware retrieves authentication tokens that should remain confidential but are instead being written to log files in clear text format. These tokens are embedded within GET URI parameters and stored in log files, making them accessible to anyone with file system access to the logging infrastructure. The vulnerability is particularly dangerous because it allows attackers to exploit this logging mechanism to extract valid authentication tokens from log files and subsequently use them to make unauthorized requests to the Swift object store by simply inserting the extracted token into the X-Auth-Token header of new HTTP requests.
This authentication bypass vulnerability directly maps to CWE-522, which addresses insufficiently protected credentials, and CWE-200, which covers exposure of sensitive information. The operational impact of this flaw extends beyond simple credential theft, as it enables attackers to gain unauthorized access to cloud storage resources, potentially leading to data breaches, unauthorized data modification, and complete compromise of the storage infrastructure. The vulnerability affects organizations using OpenStack deployments where Swauth middleware is configured, particularly those with inadequate log file access controls or insufficient monitoring of authentication-related log data. Attackers can leverage this flaw to perform unauthorized data access, data exfiltration, and potentially escalate privileges within the cloud environment.
The mitigation strategies for this vulnerability require immediate attention from system administrators and security teams. The most effective immediate solution involves updating to patched versions of both Swauth and Swift components, as the vulnerability was addressed in subsequent releases. Organizations should also implement strict log file access controls, ensuring that authentication token logs are stored in secure locations with appropriate permissions and are regularly audited for unauthorized access attempts. Additionally, implementing log file rotation and sanitization processes can prevent token exposure over time. From a defensive perspective, network monitoring should be enhanced to detect unusual patterns in X-Auth-Token header usage, and security teams should establish automated alerting mechanisms for log file access attempts. The ATT&CK framework categorizes this vulnerability under T1078 for valid accounts and T1566 for credential stuffing, as attackers can leverage stolen tokens to maintain persistent access to cloud resources. Organizations should also consider implementing multi-factor authentication mechanisms and token-based access controls to reduce the impact of credential exposure, while establishing comprehensive incident response procedures to address potential exploitation attempts.