CVE-2025-3032 is a vulnerability identified in Mozilla Firefox and Thunderbird versions earlier than 137, involving the unintended leakage of file descriptors from the fork server to web content processes. The fork server is responsible for spawning new processes efficiently, but due to improper management of file descriptors, sensitive handles may be exposed to less privileged processes. This leakage can allow malicious web content to gain access to resources or capabilities beyond their intended scope, potentially leading to privilege escalation. The vulnerability is classified under CWE-403, indicating improper restriction of operations within memory bounds. The CVSS v3.1 score is 7.4, reflecting high severity, with an attack vector of network, high attack complexity, no privileges required, no user interaction, and a scope limited to the vulnerable component. The impact includes high confidentiality and integrity loss but no availability impact. No patches were linked at the time of reporting, and no exploits are known in the wild, but the flaw poses a significant risk if exploited. The vulnerability affects a widely used browser and email client, increasing the potential attack surface globally.

If exploited, this vulnerability could allow attackers to escalate privileges within the Firefox or Thunderbird process environment, potentially accessing sensitive data or executing unauthorized actions. The confidentiality of user data and the integrity of browser and email client operations could be compromised. Since the flaw involves leaking file descriptors, attackers might gain unauthorized access to system resources or inter-process communication channels, enabling further exploitation or lateral movement. The lack of required authentication and user interaction lowers the barrier for exploitation, although the high attack complexity may limit widespread automated attacks. Organizations relying on Firefox and Thunderbird for critical communications or web access could face data breaches, espionage, or disruption of secure workflows. The vulnerability's presence in popular software increases the likelihood of targeted attacks against high-value entities.

Organizations should immediately plan to upgrade Mozilla Firefox and Thunderbird to version 137 or later once patches are released. Until then, consider restricting access to the fork server processes through OS-level controls or sandboxing to minimize exposure. Employ application whitelisting and process monitoring to detect anomalous behavior indicative of exploitation attempts. Disable or limit the use of features that spawn forked processes if feasible. Network-level protections such as web content filtering and intrusion detection systems should be tuned to identify suspicious activity related to browser processes. Regularly audit and update endpoint security solutions to detect exploitation attempts. Educate users about the risks of visiting untrusted websites, as the attack vector is network-based. Maintain up-to-date backups and incident response plans to quickly recover from potential compromises.