CVE-2012-5037 in Catalyst 7600
Summary
by MITRE
The ACL implementation in Cisco IOS before 15.1(1)SY on Catalyst 6500 and 7600 devices allows local users to cause a denial of service (device reload) via a "no object-group" command followed by an object-group command, aka Bug ID CSCts16133.
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Analysis
by VulDB Data Team • 05/11/2026
The vulnerability described in CVE-2012-5037 represents a critical denial of service flaw within the access control list implementation of Cisco IOS software running on Catalyst 6500 and 7600 series switches. This issue affects versions of IOS prior to 15.1(1)SY and demonstrates how improper handling of object-group configurations can lead to complete system failure. The vulnerability specifically manifests when a local attacker executes a sequence of commands that manipulate the object-group functionality within the device's access control mechanisms.
The technical flaw stems from insufficient input validation and memory management within the ACL processing subsystem of Cisco IOS. When a user issues the "no object-group" command followed by a subsequent object-group command with the same name, the system fails to properly handle the state transition between these operations. This command sequence creates a condition where the device's internal data structures become corrupted or improperly deallocated, leading to a system crash that ultimately results in a device reload. The vulnerability operates at the kernel level within the IOS operating system, making it particularly dangerous as it can be exploited by any local user with access to the device's command interface.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be leveraged to create persistent denial of service conditions that may require manual intervention to restore normal operations. Network administrators face the challenge of having to reboot affected devices, which can result in temporary network outages and potential loss of connectivity for services dependent on these core network devices. The vulnerability is particularly concerning in enterprise environments where these switches serve as critical infrastructure components, as unauthorized local access could lead to significant network disruptions. Additionally, the exploit requires minimal privileges and can be executed through normal administrative interfaces, making it accessible to users with basic access rights.
Mitigation strategies for CVE-2012-5037 primarily involve applying the appropriate Cisco IOS software updates that address the memory management issues within the ACL implementation. Organizations should prioritize upgrading affected Catalyst 6500 and 7600 devices to IOS version 15.1(1)SY or later, which contains the necessary patches to prevent the object-group command sequence from causing system instability. Network security teams should also implement monitoring solutions to detect unusual command patterns that might indicate exploitation attempts, while ensuring that local access to these devices is restricted through proper access control measures. The vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of how improper resource management can lead to system instability. From an ATT&CK perspective, this vulnerability falls under the T1499.004 technique for network denial of service, as it specifically targets network infrastructure devices to create service unavailability.
Organizations should conduct thorough vulnerability assessments to identify all affected devices within their network infrastructure and prioritize remediation efforts based on risk exposure. The patching process requires careful planning to minimize service disruption, as device reloads may be necessary to ensure complete remediation. Network teams should also consider implementing additional security controls such as command auditing and access restriction policies to limit the potential impact of local privilege escalation attacks. Regular security assessments and vulnerability management programs should include monitoring for similar memory corruption issues that might affect other network device models and operating systems within the enterprise environment.