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NVD / CVE Program· CNA mitre

CVE-2021-28840: 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,

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 2.3% (FIRST EPSS); higher than 83.3% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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_config function of sbin/httpd binary. When the binary handle the specific HTTP GET request, the content in upload_file variable is NULL in the upload_config function then the strncasecmp would take NULL as first argument, and incur the NULL pointer dereference vulnerability.

HighCVSS 7.5 · v3.1—No exploit No fix recorded
Published
Aug 10, 2021
Updated
Jun 16, 2026
EPSS
2.3% · 83th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 2.3%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2021-28840

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
dlinkdap-2310 firmware
dlinkdap-2310
dlinkdap-2330 firmware
dlinkdap-2330
dlinkdap-2360 firmware
dlinkdap-2360
dlinkdap-2553 firmware
dlinkdap-2553
dlinkdap-2660 firmware
dlinkdap-2660
dlinkdap-2690 firmware
dlinkdap-2690

and 6 more

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • dlink dap-2310 firmware2.0.7.rc031
  • dlink dap-2330 firmware1.07.rc028
  • dlink dap-2360 firmware2.07.rc043
  • dlink dap-2553 firmware3.06.rc027
  • dlink dap-2660 firmware1.13.rc074
  • dlink dap-2690 firmware3.16.rc100
  • dlink dap-2695 firmware1.17.rc063
  • dlink dap-3320 firmware1.01.rc014
  • dlink dap-3662 firmware1.01.rc022

Same product

dlink: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-28838Null pointer dereference vulnerability in D-Link DAP-2310 2,10RC039, DAP-2330 1.10RC036 BETA, DAP-2360 2.10RC055, DAP-2553 3.10rc039 BETA, D
    31Monitor
  • CVE-2022-38873D-Link devices DAP-2310 v2.10rc036 and earlier, DAP-2330 v1.06rc020 and earlier, DAP-2360 v2.10rc050 and earlier, DAP-2553 v3.10rc031 and ea
    30Monitor
  • CVE-2021-28839Null 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,
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records