CVE-2022-37134Public exploitNetwork attack vector

Router crash via oversized decoded L2TP username

Published Aug 22, 2022 · Updated Aug 3, 2024

Stack buffer overflow in D-Link DIR-816 A2 firmware 1.10CNB04 allows remote attackers to crash the router via a crafted L2TP username. The form2Wan.cgi handler base64-decodes l2tp_usrname when wantype is 3 and stores the decoded bytes in stack buffer v94 without checking their size. Network access to web management is sufficient because the proof of concept retrieves a token from the login page; the demonstrated consequence is a crash, not code execution.

CVSS severity9.8
Critical
EPSS probability21.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack buffer overflow in D-Link DIR-816 A2 firmware 1.10CNB04 allows remote attackers to crash the router via a crafted L2TP username. The form2Wan.cgi handler base64-decodes l2tp_usrname when wantype is 3 and stores the decoded bytes in stack buffer v94 without checking their size. Network access to web management is sufficient because the proof of concept retrieves a token from the login page; the demonstrated consequence is a crash, not code execution.

The record

CVE
CVE-2022-37134
Published
Aug 22, 2022
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-1284, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 22, 2022CVE 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

9.8NIST NVDCVSS:3.1/AV:N/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 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-1284Improper Validation of Specified Quantity in Input
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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