CVE-2024-27657Public exploit

Unauthenticated router crash via unchecked User-Agent copy

Published Feb 29, 2024 · Updated Aug 2, 2024

Stack-based buffer overflow in D-Link DIR-823G firmware 1.0.2B05 allows remote attackers to crash the router via User-Agent. The HTTP header parser copies the User-Agent value with memcpy without checking its length, causing an out-of-bounds write. No authentication or user interaction is required from an adjacent network; exploitation interrupts routing, while code execution is unconfirmed.

CVSS severity8.8
High
EPSS probability1.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in D-Link DIR-823G firmware 1.0.2B05 allows remote attackers to crash the router via User-Agent. The HTTP header parser copies the User-Agent value with memcpy without checking its length, causing an out-of-bounds write. No authentication or user interaction is required from an adjacent network; exploitation interrupts routing, while code execution is unconfirmed.

The record

CVE
CVE-2024-27657
Published
Feb 29, 2024
Updated
Aug 2, 2024
Vendor
D-Link
Product
DIR-823 Firmware
Classifications
CWE-121, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 29, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.0.2b05_20181207

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

D-Link · DIR-823 Firmwareversion=1.0.2b05_20181207

Published CVSS scores

8.8CISA-ADPCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1499.004Application or System Exploitation

Public exploit references

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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