How severe is CVE-2021-3402?

CVE-2021-3402 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 high, integrity none, and availability high.

Is CVE-2021-3402 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3402?

CVE-2021-3402 primarily affects Virustotal Yara. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-3402?

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-2021-3402 published?

CVE-2021-3402 was published on 2021-05-14 and last updated on 2026-06-17.

CVE-2021-3402

CVE-2021-3402 is a critical-severity vulnerability in Virustotal Yara 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-190.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
CVSS v2: 6.4
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-190
Affected product: Virustotal Yara
Published: 2021-05-14
Last modified: 2026-06-17

Description

An integer overflow and several buffer overflow reads in libyara/modules/macho/macho.c in YARA v4.0.3 and earlier could allow an attacker to either cause denial of service or information disclosure via a malicious Mach-O file. Affects all versions before libyara 4.0.4

Frequently asked questions

What is CVE-2021-3402?: An integer overflow and several buffer overflow reads in libyara/modules/macho/macho.c in YARA v4.0.3 and earlier could allow an attacker to either cause denial of service or information disclosure via a malicious Mach-O file. Affects all versions before libyara 4.0.4
How severe is CVE-2021-3402?: CVE-2021-3402 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 high, integrity none, and availability high.
Is CVE-2021-3402 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3402?: CVE-2021-3402 primarily affects Virustotal Yara. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-3402?: 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-2021-3402 published?: CVE-2021-3402 was published on 2021-05-14 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:virustotal:yara:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

More vulnerabilities in Virustotal Yara

CVE-2023-40857 — High (CVSS 8.8): Buffer Overflow vulnerability in VirusTotal yara v.4.3.2 allows a remote attacker to execute arbtirary code via the…
CVE-2019-19648 — High (CVSS 7.8): In the macho_parse_file functionality in macho/macho.c of YARA 3.11.0, command_size may be inconsistent with the real…
CVE-2018-12035 — High (CVSS 7.8): In YARA 3.7.1 and prior, parsing a specially crafted compiled rule file can cause an out of bounds write vulnerability…
CVE-2018-12034 — High (CVSS 7.8): In YARA 3.7.1 and prior, parsing a specially crafted compiled rule file can cause an out of bounds read vulnerability…
CVE-2017-9438 — High (CVSS 7.5): libyara/re.c in the regexp module in YARA 3.5.0 allows remote attackers to cause a denial of service (stack…
CVE-2017-9304 — High (CVSS 7.5): libyara/re.c in the regexp module in YARA 3.5.0 allows remote attackers to cause a denial of service (stack…

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