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NVD / CVE Program· CNA mitre

CVE-2021-29296: Null Pointer Dereference vulnerability in D-Link DIR-825 2.10b02, which could let a remote malicious user cause a denial of service.

Noroxi assessment

Priority: Monitor (action score 30/100)

  • 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: 1.1% (FIRST EPSS); higher than 66.2% 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 CISA the attack is automatable: targets can be found by mass scanning.
  • 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 in D-Link DIR-825 2.10b02, which could let a remote malicious user cause a denial of service. The vulnerability could be triggered by sending an HTTP request with URL /vct_wan; the sbin/httpd would invoke the strchr function and take NULL as a first argument, which finally leads to the segmentation fault. NOTE: The DIR-825 and all hardware revisions is considered End of Life and as such this issue will not be patched

HighCVSS 7.5 · v3.1—No exploit No fix recorded
Published
Aug 10, 2021
Updated
Jun 16, 2026
EPSS
1.1% · 66th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.1%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

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-2021-29296

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
dlinkdir-825 firmware
dlinkdir-825

Affected versions

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

  • dlink dir-825 firmware2.10b02

Same product

dlink: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-46442In the "webupg" binary of D-Link DIR-825 G1, attackers can bypass authentication through parameters "autoupgrade.asp", and perform functions
    56Plan
  • CVE-2021-46441In the "webupg" binary of D-Link DIR-825 G1, because of the lack of parameter verification, attackers can use "cmd" parameters to execute ar
    45Plan
  • CVE-2025-7206D-Link DIR-825 httpd switch_language.cgi sub_410DDC stack-based overflow
    42Plan

Published before and after this one in the same product

  • ← EarlierCVE-2020-10215Mar 6, 2020 · An issue was discovered on D-Link DIR-825 Rev.B 2.10 devices.
    37Monitor
  • ← EarlierCVE-2020-10216Mar 6, 2020 · An issue was discovered on D-Link DIR-825 Rev.B 2.10 devices.
    37Monitor
  • Later →CVE-2022-29332May 17, 2022 · D-LINK DIR-825 AC1200 R2 is vulnerable to Directory Traversal.
    26Monitor

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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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