CVE-2013-1838 in Compute
Summary
by MITRE
OpenStack Compute (Nova) Grizzly, Folsom (2012.2), and Essex (2012.1) does not properly implement a quota for fixed IPs, which allows remote authenticated users to cause a denial of service (resource exhaustion and failure to spawn new instances) via a large number of calls to the addFixedIp function.
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Analysis
by VulDB Data Team • 01/01/2022
The vulnerability identified as CVE-2013-1838 represents a critical resource management flaw within OpenStack Compute (Nova) components affecting versions Grizzly, Folsom, and Essex from 2012. This issue stems from inadequate implementation of fixed IP quotas, creating a significant attack surface for authenticated remote adversaries seeking to disrupt cloud infrastructure operations. The flaw specifically targets the addFixedIp function within the Nova service, which governs the allocation of fixed IP addresses to virtual machine instances within OpenStack environments.
The technical implementation of this vulnerability resides in the improper enforcement of resource limits for fixed IP address allocation within Nova's quota system. When authenticated users repeatedly invoke the addFixedIp function, the system fails to adequately track or restrict the consumption of fixed IP resources, leading to progressive resource exhaustion. This occurs because the quota enforcement mechanism does not properly account for the cumulative usage of fixed IP addresses across multiple operations, allowing attackers to consume available IP resources without appropriate limitations. The flaw essentially creates a resource leak scenario where fixed IP addresses become unavailable for legitimate instance provisioning operations, ultimately preventing new instances from being spawned successfully.
The operational impact of this vulnerability extends beyond simple denial of service, creating cascading failures within OpenStack infrastructure that can severely compromise cloud service availability. When the fixed IP pool becomes exhausted through malicious or excessive usage patterns, the Nova service enters a degraded state where it cannot allocate new fixed IP addresses required for instance creation. This results in failed instance spawning operations and can potentially bring entire compute services offline, affecting multiple tenants and applications relying on the cloud infrastructure. The vulnerability particularly impacts multi-tenant environments where resource isolation is critical, as malicious users can effectively starve other legitimate users of network resources.
Mitigation strategies for CVE-2013-1838 should focus on implementing proper quota enforcement mechanisms within the Nova service, including enhanced monitoring and rate limiting for fixed IP allocation operations. Organizations should deploy configuration changes that enforce stricter limits on fixed IP usage per tenant and implement automated alerting systems to detect unusual patterns of fixed IP consumption. The remediation process requires updating to patched versions of OpenStack Nova components where proper quota enforcement has been implemented, typically addressing the underlying CWE-1177 vulnerability category related to improper resource management. Security teams should also consider implementing network-level controls and access restrictions to limit the ability of authenticated users to perform excessive addFixedIp operations, aligning with ATT&CK technique T1499.004 for network denial of service attacks.
This vulnerability demonstrates the critical importance of proper resource management in cloud infrastructure, particularly in multi-tenant environments where resource isolation and fair usage policies must be enforced. The flaw highlights the need for comprehensive security testing of quota enforcement mechanisms and proper input validation in cloud service components. Organizations implementing OpenStack solutions must ensure that all resource allocation functions properly enforce limits to prevent similar vulnerabilities from compromising service availability and operational integrity.