CVE-2021-33592Network attack vector

Remote code execution via update-signature bypass

Published Jul 19, 2021 · Updated Aug 3, 2024

Input validation failure in NAVER Toolbar 4.0.30.323 and earlier allows remote attackers to execute arbitrary code via a crafted upgrade.xml file. Its updater accepts special characters in the filename parameter, bypassing the code-signing check applied to downloaded update content. Control of the update metadata is sufficient to make the toolbar execute attacker-supplied code without authentication or user interaction.

CVSS severity9.8
Critical
EPSS probability2.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Input validation failure in NAVER Toolbar 4.0.30.323 and earlier allows remote attackers to execute arbitrary code via a crafted upgrade.xml file. Its updater accepts special characters in the filename parameter, bypassing the code-signing check applied to downloaded update content. Control of the update metadata is sufficient to make the toolbar execute attacker-supplied code without authentication or user interaction.

The record

CVE
CVE-2021-33592
Published
Jul 19, 2021
Updated
Aug 3, 2024
Vendor
NAVER Corporation
Product
NAVER Toolbar
Classifications
CWE-20, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 19, 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?

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

  1. Affected versionversion=unspecified <=4.0.30.323

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

NAVER Corporation · NAVER Toolbarversion=unspecified <=4.0.30.323

Published CVSS scores

7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-20Improper Input Validation
T1203Exploitation for Client Execution

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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