CVE-2021-20151
Description
Trendnet AC2600 TEW-827DRU version 2.08B01 contains a flaw in the session management for the device. The router's management software manages web sessions based on IP address rather than verifying client cookies/session tokens/etc. This allows an attacker (whether from a different computer, different web browser on the same machine, etc.) to take over an existing session. This does require the attacker to be able to spoof or take over original IP address of the original user's session.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Trendnet AC2600 TEW-827DRU firmware 2.08B01 uses IP-based session management, allowing session takeover by an attacker who can spoof the victim's IP address.
Vulnerability
The Trendnet AC2600 TEW-827DRU router running firmware version 2.08B01 manages web sessions based solely on the client's IP address, without verifying session cookies or tokens [1]. This design flaw means that any request from a given IP address is treated as part of the same session, regardless of the actual client identity.
Exploitation
An attacker must be able to spoof or take over the IP address of an existing authenticated session [1]. This could be achieved from a different computer on the same network, or by manipulating network routing. No authentication or user interaction is required beyond the initial session establishment. The attacker simply sends requests from the spoofed IP to the router's management interface to assume the session.
Impact
Successful exploitation allows the attacker to take over an active administrative session, gaining the same privileges as the authenticated user [1]. This can lead to unauthorized access to the router's configuration, including viewing sensitive information (e.g., passwords, logs) and potentially modifying settings.
Mitigation
As of the publication date (2021-12-30), no firmware update has been released to address this issue [1]. Users should consider restricting access to the management interface to trusted IP addresses only, or disabling remote management if not required. The device may be end-of-life; consult Trendnet for support.
AI Insight generated on May 27, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.
Affected products
2- Trendnet/AC2600 TEW-827DRUdescription
- Range: = 2.08B01
Patches
0No patches discovered yet.
Vulnerability mechanics
Root cause
"The router's management software manages web sessions based on IP address rather than verifying client cookies or session tokens."
Attack vector
An attacker who can spoof or take over the IP address of an authenticated user's session can hijack that session without needing to know any session tokens or cookies [ref_id=1]. The attacker may be on a different computer or even a different browser on the same machine as the victim. The router's web management interface accepts any request from the same source IP as belonging to the existing authenticated session, so no additional authentication check is performed [ref_id=1]. This requires the attacker to first achieve IP spoofing or IP takeover, which raises the attack complexity (CVSS AC:H) [ref_id=1].
Affected code
The advisory [ref_id=1] does not specify particular functions, files, or code paths. The vulnerability exists in the router's management software session handling logic, which uses the client's IP address as the sole session identifier.
What the fix does
No patch is included in the bundle. The advisory [ref_id=1] identifies the root cause as IP-based session handling but does not provide a fix or remediation. To close this vulnerability, the vendor would need to implement proper session management that validates a unique session identifier (e.g., a cryptographically random token stored in a cookie or URL parameter) on every request, rather than relying solely on the client's source IP address.
Preconditions
- networkAttacker must be able to spoof or take over the original IP address of the victim's authenticated session.
- authA legitimate user must have an active authenticated session with the router's management interface.
Generated on May 25, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.
References
1- www.tenable.com/security/research/tra-2021-54mitrex_refsource_MISC
News mentions
0No linked articles in our index yet.