CVE-2025-8182 Overview
CVE-2025-8182 is a weak password requirements vulnerability affecting the Tenda AC18 router running firmware version 15.03.05.19. The flaw resides in the Samba component configuration file located at /etc_ro/smb.conf. An attacker can target this issue remotely over the network, though the attack complexity is high and exploitation is described as difficult. The weakness is tracked under CWE-521: Weak Password Requirements. Public disclosure of the issue has occurred, but no working exploit code has been observed in the wild.
Critical Impact
An attacker who successfully reaches the Samba service on a vulnerable Tenda AC18 may gain limited access to shared resources due to inadequate password policy enforcement in the shipped Samba configuration.
Affected Products
- Tenda AC18 hardware device
- Tenda AC18 firmware version 15.03.05.19
- Samba service component configured via /etc_ro/smb.conf
Discovery Timeline
- 2025-07-26 - CVE-2025-8182 published to NVD
- 2026-04-29 - Last updated in NVD database
Technical Details for CVE-2025-8182
Vulnerability Analysis
The vulnerability stems from the Samba configuration shipped in the Tenda AC18 firmware. The file /etc_ro/smb.conf defines the operating parameters for the Server Message Block (SMB) file sharing service running on the router. The configuration does not enforce password strength controls consistent with CWE-521, which permits the use of weak credentials to authenticate against shared resources.
The Samba service is reachable over the network, expanding the exposure beyond the local link. According to the advisory, the attack complexity is high and successful exploitation is considered difficult, which constrains real-world impact. The confidentiality, integrity, and availability impacts are each limited rather than complete.
Root Cause
The root cause is a configuration weakness in the read-only Samba configuration file /etc_ro/smb.conf. The configuration permits authentication policies that fall below modern minimum standards. Because the file resides under /etc_ro/, it is part of the firmware image and cannot be corrected without a firmware update from the vendor.
Attack Vector
The attack vector is network-based. An attacker who can reach the SMB service on a vulnerable AC18 may attempt credential-guessing attacks against accounts governed by the weak policy. Successful authentication grants the attacker the same level of access to Samba shares as a legitimate user under that account.
No verified exploit code is publicly available for this issue. The vulnerability is described in prose in the referenced VulDB entry #317596.
Detection Methods for CVE-2025-8182
Indicators of Compromise
- Repeated failed SMB authentication attempts originating from external or unexpected internal IP addresses against a Tenda AC18 device.
- Successful SMB logons to the router from accounts that should not be in active use.
- Unexpected file enumeration or read activity on shares exposed by the router's Samba service.
Detection Strategies
- Inspect network traffic on TCP ports 139 and 445 destined for Tenda AC18 devices and alert on authentication anomalies.
- Compare the contents of /etc_ro/smb.conf on managed devices against the vendor-supplied baseline to identify firmware running the vulnerable revision 15.03.05.19.
- Correlate SMB session establishment events with the source geolocation and time of day to surface unauthorized access.
Monitoring Recommendations
- Monitor SMB authentication logs for brute-force patterns such as high failure rates followed by a single success.
- Track firmware version inventory across deployed Tenda AC18 routers to identify devices still on 15.03.05.19.
- Alert when SMB services are reachable from untrusted network segments, which should not be the case for a consumer router.
How to Mitigate CVE-2025-8182
Immediate Actions Required
- Restrict access to the Samba service on the Tenda AC18 by blocking inbound TCP 139 and 445 at the network perimeter.
- Disable the Samba/SMB file sharing feature in the router's administration interface if it is not required.
- Rotate any credentials that have been used with the device's Samba shares and replace them with strong, unique passwords.
Patch Information
At the time of NVD publication, no vendor advisory or fixed firmware version has been published on the Tenda website. Administrators should monitor the vendor's support pages for an updated firmware release that supersedes 15.03.05.19 and addresses the weak password requirements in /etc_ro/smb.conf. Additional technical context is available in the VulDB CTI record #317596.
Workarounds
- Place the Tenda AC18 behind a firewall that blocks all external access to SMB ports 139 and 445.
- Segment the router onto a management VLAN so that only administrative hosts can reach the Samba service.
- Replace the device with hardware that supports configurable password policy enforcement if SMB sharing is operationally required.
# Example: block SMB access to the router at an upstream Linux gateway
iptables -A FORWARD -p tcp -d <AC18_IP> --dport 139 -j DROP
iptables -A FORWARD -p tcp -d <AC18_IP> --dport 445 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
