CVE-2023-52577 is a vulnerability identified in the Linux kernel's implementation of the Datagram Congestion Control Protocol (DCCP), specifically in the error handling functions dccp_v4_err() and dccp_v6_err(). The issue arises from incorrect assumptions about the structure offsets within the DCCP header, where the field dccph_x was mistakenly considered to be at byte 7 instead of byte 8. This miscalculation led to improper handling of Internet Control Message Protocol (ICMP) messages, potentially causing the kernel to process insufficiently sized ICMP packets. The vulnerability was detected through kernel memory sanitizer (KMSAN) reports indicating uninitialized value usage in the network stack, particularly within the sk_buff (socket buffer) handling code. The uninitialized memory usage can lead to undefined behavior, including potential information leakage or kernel crashes. The vulnerability affects multiple Linux kernel versions as indicated by the various commit hashes listed. The flaw is rooted in the network subsystem, involving IPv4 and IPv6 DCCP error processing paths, and impacts the kernel's ability to safely parse and respond to malformed or malicious ICMP packets. Although no known exploits are reported in the wild, the vulnerability could be leveraged by an attacker capable of sending crafted ICMP packets to trigger uninitialized memory reads or kernel faults. The issue was reported by syzbot, an automated kernel fuzzing tool, and fixed by ensuring proper validation of ICMP message sizes and correcting the offset assumptions in the DCCP header parsing logic. The vulnerability does not require authentication but does require network access to the affected system's DCCP services or interfaces that process ICMP messages. The lack of a CVSS score necessitates an expert severity assessment based on the technical details.

For European organizations, this vulnerability poses a risk primarily to systems running vulnerable Linux kernel versions that utilize DCCP, which is often used in specialized network applications requiring congestion control, such as multimedia streaming or telephony over IP. Exploitation could lead to kernel crashes (denial of service) or potential information leakage through uninitialized memory reads, undermining system stability and confidentiality. Critical infrastructure, telecommunications providers, and enterprises relying on Linux-based network appliances or servers could be affected, potentially disrupting services or exposing sensitive data. Given the kernel-level nature of the flaw, successful exploitation could allow attackers to escalate privileges or cause system instability, impacting availability and integrity. The threat is heightened in environments with exposed network interfaces or where ICMP traffic is not adequately filtered. European organizations with stringent uptime and data protection requirements may face operational and compliance risks if vulnerable systems are exploited.

1. Immediate application of the official Linux kernel patches that correct the DCCP header offset and improve ICMP message size validation is essential. Organizations should track kernel updates from their Linux distribution vendors and deploy security updates promptly. 2. Network administrators should implement strict ingress and egress filtering to limit ICMP traffic to trusted sources, reducing the attack surface. 3. Disable DCCP protocol support on systems where it is not required to eliminate exposure. 4. Employ kernel hardening techniques such as enabling Kernel Address Sanitizer (KASAN) and Kernel Memory Sanitizer (KMSAN) in testing environments to detect similar issues proactively. 5. Monitor network traffic for anomalous ICMP packets that could indicate exploitation attempts. 6. For critical systems, consider deploying intrusion detection/prevention systems (IDS/IPS) capable of recognizing malformed ICMP or DCCP packets. 7. Conduct regular vulnerability assessments and penetration testing focusing on network protocol handling to identify residual risks.