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Fencer Vulns
critical 9.8

CVE-2020-15892 json

An issue was discovered in apply.cgi on D-Link DAP-1520 devices before 1.10b04Beta02.

published 2020-07-22 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-7866

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 76%
public exploits
0
none known

Summary

An issue was discovered in apply.cgi on D-Link DAP-1520 devices before 1.10b04Beta02. Whenever a user performs a login action from the web interface, the request values are being forwarded to the ssi binary. On the login page, the web interface restricts the password input field to a fixed length of 15 characters. The problem is that validation is being done on the client side, hence it can be bypassed. When an attacker manages to intercept the login request (POST based) and tampers with the vulnerable parameter (log_pass), to a larger length, the request will be forwarded to the webserver. This results in a stack-based buffer overflow. A few other POST variables, (transferred as part of the login request) are also vulnerable: html_response_page and log_user.

Patch / fix

Exploit prediction

1.64% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • research.loginsoft.com https://research.loginsoft.com/bugs/classic-stack-based-buffer-overflow-in-dlink-firmware-dap-1520/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness
  • CWE-669 Incorrect Resource Transfer Between Spheres
  • CWE-787 Out-of-bounds Write

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.