CVE-2023-43314Public exploitNetwork attack vector

Unauthenticated web-service crash via oversized uid parsing

Published Sep 27, 2023 · Updated Aug 2, 2024

Buffer overflow in Zyxel PMG2005-T20B firmware V1.00(ABNK.2)b11_C0 allows remote attackers to crash its web service via a crafted uid. The login CGI backend parses an oversized uid cookie value without enforcing the input bound needed before copying it, causing the web application to terminate. Network access to the management interface is sufficient; successful exploitation interrupts that interface, with no reported confidentiality or integrity impact.

CVSS severity7.5
High
EPSS probability0.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in Zyxel PMG2005-T20B firmware V1.00(ABNK.2)b11_C0 allows remote attackers to crash its web service via a crafted uid. The login CGI backend parses an oversized uid cookie value without enforcing the input bound needed before copying it, causing the web application to terminate. Network access to the management interface is sufficient; successful exploitation interrupts that interface, with no reported confidentiality or integrity impact.

The record

CVE
CVE-2023-43314
Published
Sep 27, 2023
Updated
Aug 2, 2024
Vendor
Zyxel Networks
Product
PMG2005-T20B
Classifications
CWE-120, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 27, 2023CVE 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=V1.00(ABNK.2)b11_C0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zyxel Networks · PMG2005-T20Bversion=V1.00(ABNK.2)b11_C0

Published CVSS scores

7.5Zyxel CorporationCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 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 exploitPublished

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1499.004Application or System Exploitation

Public exploit references

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Technologies

Your stack

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Your stack

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