CVE-2013-1827 in Linux
Summary
by MITRE
net/dccp/ccid.h in the Linux kernel before 3.5.4 allows local users to gain privileges or cause a denial of service (NULL pointer dereference and system crash) by leveraging the CAP_NET_ADMIN capability for a certain (1) sender or (2) receiver getsockopt call.
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Analysis
by VulDB Data Team • 05/06/2021
The vulnerability identified as CVE-2013-1827 resides within the Linux kernel's implementation of the Datagram Congestion Control Protocol (DCCP) subsystem, specifically in the ccid.h header file. This flaw represents a critical security issue that affects Linux kernel versions prior to 3.5.4, where local attackers with the CAP_NET_ADMIN capability can exploit a NULL pointer dereference condition. The vulnerability manifests during specific getsockopt system calls made by either DCCP sender or receiver components, creating a pathway for privilege escalation or system instability. The DCCP protocol is designed for applications requiring congestion control over unreliable transport, making this vulnerability particularly concerning for systems that utilize DCCP networking.
The technical exploitation of this vulnerability occurs through a carefully crafted sequence of operations that leverage the CAP_NET_ADMIN capability, which grants network administration privileges to processes. When a process with this capability makes certain getsockopt calls to DCCP socket objects, the kernel's CCID (Congestion Control ID) implementation fails to properly validate pointer references before dereferencing them. This NULL pointer dereference results in a kernel panic, causing the system to crash and potentially leading to a denial of service condition that can be exploited by malicious local users. The flaw exists in the kernel's socket option handling logic where the code path does not adequately check for NULL values before accessing memory locations, directly violating secure coding practices that should prevent such dereferences.
The operational impact of CVE-2013-1827 extends beyond simple system crashes, as it provides a potential vector for privilege escalation within compromised systems. Local attackers who already possess the CAP_NET_ADMIN capability can leverage this vulnerability to either gain higher privileges or cause persistent denial of service conditions that may be difficult to recover from without manual intervention. The vulnerability affects systems that have DCCP support compiled into their kernel or have DCCP modules loaded, making it particularly relevant for network infrastructure servers, routers, and systems that utilize DCCP for specific applications. Organizations running affected kernel versions face significant risk as this vulnerability can be exploited without requiring additional privileges beyond what is already available to network administrators.
Mitigation strategies for CVE-2013-1827 primarily focus on kernel version updates, with the most effective solution being the upgrade to Linux kernel version 3.5.4 or later where the vulnerability has been patched. System administrators should also consider implementing proper access controls to limit the distribution of CAP_NET_ADMIN capabilities to processes that require them, following the principle of least privilege. Additional defensive measures include monitoring for unusual socket operations and implementing kernel hardening techniques such as stack canaries and address space layout randomization. The vulnerability aligns with CWE-476 which describes NULL pointer dereference conditions, and represents a potential ATT&CK technique under privilege escalation and denial of service tactics. Organizations should also consider disabling DCCP support entirely if the protocol is not required for their specific use cases, reducing the attack surface and eliminating the risk associated with this particular vulnerability.