CVE-2021-45940

Exp

libbpf 0.6.0 and 0.6.1 has a heap-based buffer overflow (4 bytes) in __bpf_object__open (called from bpf_object__open_mem and bpf-object-fuzzer.c).

Published: 2022-01-01 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-45940 is rated High Exploit Risk (63.4/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.12%). 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-2021-45940

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-2021-45940

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 2026-06-15 0.37% 1.12% +0.76%
2 2026-06-09 0.23% 0.37% +0.14%
3 2026-01-27 — 0.23% —

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-45940

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful 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.
 2.8 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2021-45940

OS Trackers for CVE-2021-45940

vendor priority summary link
debian not yet assigned CVE-2021-45940 not yet assigned priority: Debian including 1 source packages (libbpf), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2021-45940
redhat low — https://access.redhat.com/security/cve/CVE-2021-45940
suse medium CVE-2021-45940 severity moderate: SUSE including 16 source package names (libbpf, libbpf-devel-1.0.1-2.1, …), 19 product×package rows across 12 product lines (SUSE Linux Enterprise Micro 5.5, SUSE Linux Enterprise Module for Basesystem 15 SP4, … (12 product lines)): Fixed 15, Known Not Affected 4. https://www.suse.com/security/cve/CVE-2021-45940/
ubuntu medium CVE-2021-45940 medium priority: Ubuntu including 1 source packages (libbpf), 8 status rows across 8 suites (focal, hirsute, impish, jammy, kinetic, trusty, upstream, xenial): ignored 4, not-affected 2, needs-triage 1, released 1. https://ubuntu.com/security/CVE-2021-45940

Affected software / configurations for CVE-2021-45940

Vendor Product Version Raw CPE
libbpf_project libbpf 0.6.0 cpe:2.3:a:libbpf_project:libbpf:0.6.0:*:*:*:*:*:*:*
libbpf_project libbpf 0.6.1 cpe:2.3:a:libbpf_project:libbpf:0.6.1:*:*:*:*:*:*:*

References for CVE-2021-45940

cvelogic Threat Intelligence