CVE-2010-2949 in Quagga
Summary
by MITRE
bgpd in Quagga before 0.99.17 does not properly parse AS paths, which allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via an unknown AS type in an AS path attribute in a BGP UPDATE message.
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Analysis
by VulDB Data Team • 09/24/2021
The vulnerability identified as CVE-2010-2949 affects the bgpd daemon within Quagga routing software versions prior to 0.99.17. This issue represents a critical flaw in the Border Gateway Protocol implementation that governs internet routing operations. The vulnerability specifically targets the AS path attribute parsing mechanism within BGP UPDATE messages, which are fundamental components of the routing protocol used to exchange routing information between different autonomous systems on the internet. When a malicious actor crafts a BGP UPDATE message containing an invalid or unexpected AS type within the AS path attribute, the bgpd daemon fails to properly handle this malformed data, leading to system instability.
The technical exploitation of this vulnerability occurs through a NULL pointer dereference condition that results from improper input validation during AS path parsing operations. When the bgpd daemon encounters an unknown AS type in the AS path attribute of a BGP UPDATE message, the parsing routine fails to adequately validate the input data structure before attempting to access memory locations. This failure creates a scenario where the daemon attempts to dereference a null pointer, causing an immediate crash of the bgpd process. The vulnerability stems from insufficient bounds checking and input sanitization within the BGP attribute processing code, allowing attackers to inject malformed data that triggers the exploitable condition.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the stability of entire routing infrastructure. Network operators relying on Quagga-based routing systems face significant risk of unauthorized denial of service attacks that can disrupt routing operations and potentially cause cascading failures throughout connected networks. The daemon crash affects not only the immediate routing functionality but can also impact the overall reliability of the routing domain, as BGP peers may need to re-establish connections and re-synchronize routing tables. This vulnerability particularly affects internet service providers and network infrastructure operators who depend on stable BGP implementations for maintaining connectivity and routing stability across their networks.
Mitigation strategies for this vulnerability include immediate deployment of Quagga version 0.99.17 or later, which contains the necessary patches to properly handle malformed AS path attributes. Network administrators should implement BGP monitoring and anomaly detection systems to identify potentially malicious BGP UPDATE messages before they can trigger the vulnerability. The fix addresses the underlying CWE-476 weakness related to NULL pointer dereference, which is categorized under the broader class of input validation issues in the Common Weakness Enumeration framework. Additionally, implementing BGP security measures such as route filtering, prefix filtering, and proper BGP session authentication can help reduce the attack surface and prevent exploitation of this vulnerability. Organizations should also consider implementing network segmentation and access control measures to limit exposure to potentially malicious BGP traffic from untrusted sources. The vulnerability aligns with ATT&CK technique T1566 related to credential access through network service providers, as it can be leveraged to disrupt network operations and potentially gain further access to compromised routing infrastructure.