CVE-2014-7960 in Swift
Summary
by MITRE
OpenStack Object Storage (Swift) before 2.2.0 allows remote authenticated users to bypass the max_meta_count and other metadata constraints via multiple crafted requests which exceed the limit when combined.
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Analysis
by VulDB Data Team • 03/30/2022
The vulnerability identified as CVE-2014-7960 affects OpenStack Object Storage (Swift) versions prior to 2.2.0, representing a significant security flaw that undermines the platform's metadata management controls. This issue stems from a design weakness in how Swift handles metadata constraints, specifically targeting the max_meta_count parameter and related metadata limits that are fundamental to maintaining storage system integrity and preventing resource exhaustion attacks. The vulnerability operates by exploiting the way Swift processes multiple metadata requests, allowing authenticated attackers to circumvent imposed limits through carefully constructed sequences of individual requests that, when aggregated, exceed the configured constraints.
The technical implementation of this vulnerability exploits a fundamental flaw in Swift's metadata validation logic, where individual requests are validated against limits but the cumulative effect of multiple requests is not properly tracked or enforced. This creates a scenario where an attacker can submit numerous small metadata updates that individually remain within acceptable limits, yet collectively exceed the maximum allowed metadata count or other constraints. The flaw is particularly insidious because it operates within the legitimate authentication framework, meaning that only authenticated users can exploit this vulnerability, but these users can do so without triggering immediate detection mechanisms that might otherwise flag suspicious activity patterns.
From an operational impact perspective, this vulnerability presents a serious risk to OpenStack Swift deployments as it enables authenticated users to potentially consume excessive system resources through metadata manipulation. Attackers could leverage this to exhaust storage system resources, degrade performance, or create denial of service conditions by accumulating metadata beyond the intended limits. The vulnerability also compromises the security posture of the storage system by allowing unauthorized resource consumption that bypasses administrative controls designed to prevent such scenarios. This represents a critical failure in the principle of least privilege and resource management, as legitimate authenticated users can exploit this weakness to gain disproportionate access to system resources.
The mitigation strategy for CVE-2014-7960 requires immediate deployment of OpenStack Swift version 2.2.0 or later, which includes the necessary fixes to properly enforce metadata constraints across multiple requests. Organizations should also implement additional monitoring and logging controls to detect unusual metadata update patterns that might indicate exploitation attempts. The fix addresses the underlying CWE-129 weakness related to improper validation of input boundaries and implements proper cumulative tracking of metadata constraints. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and resource exhaustion, specifically targeting the T1499.004 sub-technique related to resource exhaustion and T1078.004 related to valid accounts. System administrators should also consider implementing rate limiting and request aggregation controls to provide additional defense-in-depth measures against similar vulnerabilities in the metadata handling subsystem.
This vulnerability demonstrates the critical importance of proper input validation and cumulative constraint enforcement in distributed storage systems, where individual security controls may be bypassed through sophisticated attack patterns that exploit logical gaps in validation logic. The issue highlights the need for comprehensive testing of boundary conditions and the implementation of robust validation mechanisms that consider the aggregate impact of multiple operations rather than just individual transactional validity. Organizations utilizing OpenStack Swift must prioritize this patch deployment and conduct thorough security assessments to ensure that their metadata management policies are properly enforced across all system components and access methods.