CVE-2023-5594Network attack vector

Browser trust bypass via obsolete intermediate signatures

Published Dec 21, 2023 · Updated Aug 2, 2024

Improper certificate validation in ESET security products allows remote attackers to make browsers trust sites using obsolete signatures. The secure traffic scanning feature treats an intermediate certificate signed with MD5 or SHA-1 as trusted instead of rejecting the server chain. Exploitation requires secure traffic scanning to be enabled and permits acceptance of an otherwise untrusted site; no service interruption is reported.

CVSS severity7.5
High
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper certificate validation in ESET security products allows remote attackers to make browsers trust sites using obsolete signatures. The secure traffic scanning feature treats an intermediate certificate signed with MD5 or SHA-1 as trusted instead of rejecting the server chain. Exploitation requires secure traffic scanning to be enabled and permits acceptance of an otherwise untrusted site; no service interruption is reported.

The record

CVE
CVE-2023-5594
Published
Dec 21, 2023
Updated
Aug 2, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-295, CAPEC-459, CAPEC-475, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 21, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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

7.5ESETCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N
8.6NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

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-295Improper Certificate Validation
CAPEC-459Creating a Rogue Certification Authority Certificate
CAPEC-475Signature Spoofing by Improper Validation
T1557Adversary-in-the-Middle

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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