PT-2021-17962 · Trendnet · Trendnet Tew-821Dap2Kac+3

Published 2021-08-10 · Updated 2021-08-19 · CVE-2021-28846

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions: TRENDnet TEW-755AP version 1.11B03 TRENDnet TEW-755AP2KAC version 1.11B03 TRENDnet TEW-821DAP2KAC version 1.11B03 TRENDnet TEW-825DAP version 1.11B03

Description: A Format String issue exists, which could let a remote malicious user cause a denial of service due to a logic bug at address 0x40dcd0 when calling fprintf with "%s: key len = %d, too long " format. The two variables seem to be put in the wrong order. The issue could be triggered by sending the POST request to "apply cgi" with a long and unknown key in the request body.

Recommendations: For TRENDnet TEW-755AP version 1.11B03, consider disabling the apply cgi endpoint until a patch is available. For TRENDnet TEW-755AP2KAC version 1.11B03, consider disabling the apply cgi endpoint until a patch is available. For TRENDnet TEW-821DAP2KAC version 1.11B03, consider disabling the apply cgi endpoint until a patch is available. For TRENDnet TEW-825DAP version 1.11B03, consider disabling the apply cgi endpoint until a patch is available. As a temporary workaround, avoid using the apply cgi endpoint with a long and unknown key in the request body until the issue is resolved.

Fix

Use of Externally-Controlled Format String

Weakness Enumeration

CWE-134

Related Identifiers

CVE-2021-28846

Affected Products

Trendnet Tew755Ap

Trendnet Tew-755Ap2Kac

Trendnet Tew-821Dap2Kac

Trendnet Tew-825Dap

References · 5

• https://osv.dev/vulnerability/CVE-2021-28846 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-28846 · Security Note
• https://github.com/zyw-200/EQUAFL/blob/main/TRENDnet%20ticket.pdf · Note
• https://t.me/cvenotify/19043 · Telegram Post
• https://t.me/cibsecurity/27102 · Telegram Post