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Fencer Vulns
high 7.5

CVE-2021-28839 json

Null Pointer Dereference vulnerability exists in D-Link DAP-2310 2.07.RC031, DAP-2330 1.07.RC028, DAP-2360 2.07.RC043, DAP-2553 3.06.RC027,…

published 2021-08-10 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-15493

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.4%
EPSS 1.4% chance of exploitation in 30 days, percentile 72%
public exploits
0
none known

Summary

Null Pointer Dereference vulnerability exists in D-Link DAP-2310 2.07.RC031, DAP-2330 1.07.RC028, DAP-2360 2.07.RC043, DAP-2553 3.06.RC027, DAP-2660 1.13.RC074, DAP-2690 3.16.RC100, DAP-2695 1.17.RC063, DAP-3320 1.01.RC014 and DAP-3662 1.01.RC022 in the upload_certificate function of sbin/httpd binary. When the binary handle the specific HTTP GET request, the strrchr in the upload_certificate function would take NULL as first argument, and incur the NULL pointer dereference vulnerability.

Exploit prediction

1.38% chance of exploitation in the next 30 days, higher than 72% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/zyw-200/EQUAFL/blob/main/dlink-email-cve.pdf referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness

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.