CVE-2021-30072Network attack vector

Unauthenticated service crash via prog.cgi strcat overflow

Published Apr 2, 2021 · Updated Aug 3, 2024

A stack-based buffer overflow in D-Link DIR-878 1.30B08 and earlier allows remote attackers on the LAN to crash the prog.cgi process. The main function passes request-derived data to strcat without enforcing the destination stack buffer's capacity, causing an out-of-bounds write. No authentication is required, but access is limited to the LAN side; the resulting process crash causes the router to malfunction.

CVSS severity9.8
Critical
EPSS probability1.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A stack-based buffer overflow in D-Link DIR-878 1.30B08 and earlier allows remote attackers on the LAN to crash the prog.cgi process. The main function passes request-derived data to strcat without enforcing the destination stack buffer's capacity, causing an out-of-bounds write. No authentication is required, but access is limited to the LAN side; the resulting process crash causes the router to malfunction.

The record

CVE
CVE-2021-30072
Published
Apr 2, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 2, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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