CVE-2025-13945 is a vulnerability identified in Wireshark version 4.6.0, specifically within the HTTP3 protocol dissector component. The root cause is an improperly controlled sequential memory allocation, categorized under CWE-1325, which leads to a crash when processing certain malformed HTTP3 packets. This crash results in a denial of service condition by terminating the Wireshark process unexpectedly. The vulnerability requires an attacker to provide crafted HTTP3 traffic that triggers the memory allocation flaw. Exploitation does not require privileges but does require user interaction, as the victim must open or analyze the malicious packet capture or live traffic. The CVSS v3.1 base score is 5.5, reflecting medium severity, with the vector indicating local attack vector (AV:L), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), unchanged scope (S:U), no impact on confidentiality or integrity (C:N/I:N), and high impact on availability (A:H). There are no known exploits in the wild, and no patches have been released at the time of publication. This vulnerability could be leveraged by attackers to disrupt network analysis and monitoring activities, potentially delaying incident response or forensic investigations.

The primary impact of CVE-2025-13945 is denial of service against Wireshark users, causing the application to crash when processing malicious HTTP3 traffic. This can disrupt network traffic analysis, incident response, and forensic investigations, especially in environments where Wireshark is a critical tool for real-time monitoring or troubleshooting. Although the vulnerability does not compromise data confidentiality or integrity, the loss of availability can hinder security operations and delay detection of other threats. Organizations relying heavily on Wireshark for network diagnostics, particularly those analyzing HTTP3 traffic, may experience operational interruptions. The requirement for user interaction and local access limits remote exploitation, reducing the overall risk to large-scale automated attacks. However, targeted attackers could exploit this vulnerability to disrupt specific analysts or teams.

Since no official patch is currently available, organizations should implement several practical mitigations: 1) Avoid opening or analyzing untrusted or suspicious HTTP3 packet captures in Wireshark 4.6.0. 2) Use network segmentation and filtering to limit exposure to potentially malicious HTTP3 traffic, especially from untrusted sources. 3) Employ alternative or updated network analysis tools that do not exhibit this vulnerability when handling HTTP3 traffic. 4) Monitor Wireshark usage and crashes closely to detect potential exploitation attempts. 5) Educate analysts to be cautious with HTTP3 traffic and to report crashes immediately. Once a patch is released, prioritize timely updates to Wireshark to remediate the vulnerability. Additionally, consider running Wireshark in isolated environments or virtual machines to contain potential crashes and reduce impact on critical systems.