CVE-2025-52363 is a vulnerability identified in the firmware of the Tenda CP3 Pro router, specifically version V22.5.4.93. The issue arises from the presence of a hardcoded root password hash embedded within the /etc/passwd and /etc/passwd- files of the firmware image. This means that anyone with access to the firmware image can extract this password hash and attempt to crack it offline. If successful, the attacker gains root-level administrative access to the device. Root access on a router allows full control over the device, including the ability to modify configurations, intercept or redirect network traffic, install persistent malware, or use the device as a foothold for further attacks within the network. The vulnerability does not require the attacker to have prior access to the device itself; possession of the firmware image alone is sufficient to start an attack. Although no known exploits are currently reported in the wild, the presence of a hardcoded root password hash is a critical security flaw that significantly lowers the barrier for attackers to compromise affected devices once the password hash is cracked. The lack of a CVSS score indicates that this vulnerability has not yet been formally scored, but the technical details suggest a high-risk issue due to the potential for full device compromise and network infiltration.

For European organizations, the exploitation of this vulnerability could have severe consequences. Many enterprises and small businesses rely on consumer-grade or SMB-grade routers like the Tenda CP3 Pro for network connectivity. If attackers gain root access to these routers, they can manipulate network traffic, conduct man-in-the-middle attacks, exfiltrate sensitive data, or create persistent backdoors. This is particularly concerning for organizations handling sensitive personal data under GDPR regulations, as unauthorized access and data breaches could lead to significant legal and financial penalties. Additionally, compromised routers can be leveraged as part of botnets or for launching attacks against other targets, amplifying the threat landscape. The vulnerability also poses risks to critical infrastructure sectors that may use such devices for network access, potentially disrupting operations or compromising safety. Given the ease of extracting the password hash from publicly available firmware images, the threat is not limited to targeted attacks but could be exploited opportunistically by a wide range of adversaries.

Organizations should immediately verify if they use Tenda CP3 Pro routers with the affected firmware version V22.5.4.93. If so, they should check for firmware updates or patches from Tenda that address this vulnerability. In the absence of an official patch, it is advisable to replace affected devices with models that do not contain hardcoded credentials. Network administrators should also change default passwords on all devices and implement network segmentation to limit the exposure of critical systems. Monitoring network traffic for unusual activity and deploying intrusion detection systems can help identify potential exploitation attempts. Additionally, organizations should restrict access to firmware images and avoid downloading firmware from untrusted sources to reduce the risk of attackers obtaining the password hash. For environments where these routers are used, consider implementing multi-factor authentication on network management interfaces and disabling remote management features if not required.