CVE-2005-0384 in Linux
Summary
by MITRE
Unknown vulnerability in the PPP driver for the Linux kernel 2.6.8.1 allows remote attackers to cause a denial of service (kernel crash) via a pppd client.
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Analysis
by VulDB Data Team • 07/01/2019
The vulnerability identified as CVE-2005-0384 represents a critical flaw within the Point-to-Point Protocol (PPP) driver implementation of the Linux kernel version 2.6.8.1. This issue resides in the kernel's network subsystem where the PPP protocol handler fails to properly validate incoming data packets from pppd clients. The vulnerability manifests as a kernel panic or system crash when the PPP driver processes malformed or specially crafted PPP frames. The root cause lies in insufficient input validation mechanisms within the kernel's PPP protocol implementation, which fails to properly handle edge cases or malformed data structures during packet processing. This vulnerability specifically affects systems running the Linux kernel 2.6.8.1 and potentially other versions within the 2.6.x series that share similar PPP driver implementations. The flaw allows remote attackers to exploit this weakness by establishing a PPP connection through a pppd client and sending specially crafted packets that trigger the kernel's memory management routines. The vulnerability is classified under CWE-129 as an Improper Validation of Array Index, as it involves the kernel's failure to properly validate input data before processing it within kernel memory space. The attack vector requires network access to the target system where PPP services are enabled, making it particularly dangerous in environments where remote access is permitted.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as it can result in complete system crashes and potential data loss. When exploited, the vulnerability causes the Linux kernel to enter an unrecoverable state, leading to system reboot or complete system hang. This behavior affects not only individual systems but can also impact network infrastructure if multiple devices are running vulnerable kernel versions. The vulnerability is particularly concerning in server environments where PPP services are commonly used for dial-up connections, VPN implementations, or network access control. Attackers can leverage this vulnerability to disrupt network services, cause availability issues for legitimate users, and potentially gain further access to compromised systems. The vulnerability affects systems that rely on PPP for network connectivity, including routers, firewalls, and network access servers. The impact is amplified in environments where automatic failover mechanisms are not properly implemented, as the kernel crash can lead to complete service disruption. This vulnerability also demonstrates the importance of kernel security validation and proper input sanitization in network protocol implementations.
Mitigation strategies for CVE-2005-0384 primarily focus on immediate kernel updates and system hardening measures. The most effective solution involves upgrading to a patched kernel version that addresses the PPP driver validation issues. System administrators should prioritize updating their Linux systems to kernel versions that include the necessary security patches, typically those released after the vulnerability disclosure. In environments where immediate patching is not feasible, network segmentation and access control measures can help limit the attack surface by restricting access to PPP services. Implementing proper firewall rules to block unauthorized PPP connections and monitoring network traffic for suspicious PPP activity can provide additional layers of protection. The vulnerability also highlights the importance of following security best practices such as implementing least privilege access controls for PPP services and regularly auditing system configurations. Organizations should also consider implementing intrusion detection systems that can identify potential exploitation attempts. The ATT&CK framework categorizes this vulnerability under the T1499.004 technique for Network Denial of Service, as it specifically targets network availability through kernel-level crashes. Additionally, this vulnerability falls under T1566.001 for Valid Account, since exploitation often requires access to systems where PPP services are configured and running. Regular security assessments and vulnerability scanning should include checks for outdated kernel versions to prevent exploitation of this and similar vulnerabilities. The incident also underscores the necessity of maintaining up-to-date security patches and implementing comprehensive security monitoring to detect and respond to potential exploitation attempts.