CVE-2021-3402

Exp

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

Published: 2021-05-14 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-3402 is rated High Exploit Risk (74/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 0.47%). 2 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-3402

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-3402

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-21 0.57% 0.47% -0.10%
2 2026-04-27 1.41% 0.57% -0.84%
3 2026-01-15 — 1.41% —

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3402

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.2 [email protected]
6.4 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 4.9 [email protected]

Weakness enumeration for CVE-2021-3402

OS Trackers for CVE-2021-3402

vendor priority summary link
debian not yet assigned CVE-2021-3402 not yet assigned priority: Debian including 1 source packages (yara), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-3402
ubuntu medium CVE-2021-3402 medium priority: Ubuntu including 1 source packages (yara), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 9, ignored 4, released 2, DNE 1. https://ubuntu.com/security/CVE-2021-3402

Affected software / configurations for CVE-2021-3402

Vendor Product Version Raw CPE
virustotal yara < 4.0.4 cpe:2.3:a:virustotal:yara:*:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

References for CVE-2021-3402

cvelogic Threat Intelligence