How severe is CVE-2023-29487?

CVE-2023-29487 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.

Is CVE-2023-29487 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-29487?

CVE-2023-29487 affects Heimdalsecurity Thor. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-29487?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2023-29487 published?

CVE-2023-29487 was published on 2023-12-21 and last updated on 2026-06-17.

CVE-2023-29487

CVE-2023-29487 is a critical-severity vulnerability in Heimdalsecurity Thor with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1333.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 1% (47th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-1333
Affected product: Heimdalsecurity Thor
Published: 2023-12-21
Last modified: 2026-06-17

Description

An issue was discovered in Heimdal Thor agent versions 3.4.2 and before on Windows and 2.6.9 and before on macOS, allows attackers to cause a denial of service (DoS) via the Threat To Process Correlation threat prevention module. NOTE: Heimdal asserts this is not a valid vulnerability. Their DNS Security for Endpoint solution includes an optional feature to provide extra information on the originating process that made a DNS request. The lack of process identification in DNS logs is therefore falsely categorized as a DoS issue.

Frequently asked questions

What is CVE-2023-29487?: An issue was discovered in Heimdal Thor agent versions 3.4.2 and before on Windows and 2.6.9 and before on macOS, allows attackers to cause a denial of service (DoS) via the Threat To Process Correlation threat prevention module. NOTE: Heimdal asserts this is not a valid vulnerability. Their DNS Security for Endpoint solution includes an optional feature to provide extra information on the originating process that made a DNS request. The lack of process identification in DNS logs is therefore falsely categorized as a DoS issue.
How severe is CVE-2023-29487?: CVE-2023-29487 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.
Is CVE-2023-29487 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-29487?: CVE-2023-29487 affects Heimdalsecurity Thor. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-29487?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2023-29487 published?: CVE-2023-29487 was published on 2023-12-21 and last updated on 2026-06-17.

References

https://medium.com/%40drabek.a/weaknesses-in-heimdal-thors-line-of-products-9d0e5095fb93

Affected products (1)

cpe:2.3:a:heimdalsecurity:thor:*:*:*:*:*:*:*:*

More vulnerabilities in Heimdalsecurity Thor

CVE-2023-29486 — Critical (CVSS 9.8): An issue was discovered in Heimdal Thor agent versions 3.4.2 and before 3.7.0 on Windows, allows attackers to bypass…
CVE-2023-29485 — Critical (CVSS 9.8): An issue was discovered in Heimdal Thor agent versions 3.4.2 and before on Windows and 2.6.9 and before on macOS,…
CVE-2019-8351 — Critical (CVSS 9.1): Heimdal Thor Agent 2.5.17x before 2.5.173 does not verify X.509 certificates from TLS servers, which allows remote…

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