CVE-2008-3807 in IOS
Summary
by MITRE
Cisco IOS 12.2 and 12.3 on Cisco uBR10012 series devices, when linecard redundancy is configured, enables a read/write SNMP service with "private" as the community, which allows remote attackers to obtain administrative access by guessing this community and sending SNMP requests.
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Analysis
by VulDB Data Team • 08/17/2019
The vulnerability described in CVE-2008-3807 represents a critical security flaw in Cisco IOS software versions 12.2 and 12.3 that affects uBR10012 series devices operating with linecard redundancy configurations. This issue stems from a misconfiguration that inadvertently exposes a read/write SNMP service with a well-known default community string of "private" when redundant linecards are enabled. The flaw exists within the network infrastructure equipment that serves as a critical component in service provider networks, making it particularly concerning for organizations relying on Cisco's routing and switching solutions for their core network operations.
The technical implementation of this vulnerability occurs when linecard redundancy is configured on affected Cisco uBR10012 devices, causing the system to automatically enable SNMP services with the "private" community string without proper access controls or authentication mechanisms. This default community string, which is widely known within the cybersecurity community, provides full read-write access to the device's management interface. Attackers can exploit this by simply guessing the community string and sending crafted SNMP requests to the device, effectively bypassing normal authentication procedures and gaining administrative privileges over the affected router. The vulnerability aligns with CWE-255 - Improper Handling of Credentials, as it involves the improper handling of default credentials that should be changed but remain unchanged in the vulnerable configuration.
The operational impact of this vulnerability is severe and far-reaching for organizations using affected Cisco equipment in their network infrastructure. Remote attackers who discover or guess the "private" community string can execute arbitrary commands, modify device configurations, access sensitive network information, and potentially disrupt network services. This capability allows threat actors to perform reconnaissance, establish persistent access points, and conduct advanced persistent threats against the affected network segments. The vulnerability particularly affects service provider networks where uBR10012 devices serve as critical edge routers, potentially enabling attackers to compromise entire network domains through lateral movement and privilege escalation. This issue maps to several ATT&CK techniques including T1078 - Valid Accounts, T1046 - Network Service Scanning, and T1566 - Phishing, as attackers can leverage the exposed SNMP service to gain unauthorized access and potentially escalate privileges through network reconnaissance.
Organizations should immediately implement comprehensive mitigation strategies to address this vulnerability. The primary recommendation involves changing the default SNMP community strings to strong, unique values that are not publicly known or easily guessable. Network administrators should disable SNMP services when not required, implement proper network segmentation to limit access to management interfaces, and enforce strict access controls for SNMP operations. The configuration should include disabling the automatic enabling of SNMP services when linecard redundancy is configured, and implementing network access control lists to restrict SNMP traffic to authorized management stations only. Additionally, organizations should conduct regular security audits of their network infrastructure to identify and remediate similar misconfigurations, ensuring that default credentials are changed and that proper security controls are in place to prevent unauthorized access to critical network equipment. This vulnerability demonstrates the importance of proper configuration management and the need for regular security assessments to identify and remediate potential security gaps in network infrastructure deployments.