CVE-2021-44847

Exp

A stack-based buffer overflow in handle_request function in DHT.c in toxcore 0.1.9 through 0.1.11 and 0.2.0 through 0.2.12 (caused by an improper length calculation during the handling of received network packets) allows remote attackers to crash the process or potentially execute arbitrary code via a network packet.

Published: 2021-12-13 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-44847 is rated High Exploit Risk (85/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 3.95%). 1 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-2021-44847

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

Exploit prediction scoring system (EPSS) score for CVE-2021-44847

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 2026-01-29 3.96% 3.95% -0.01%
2 2026-01-14 2.23% 3.96% +1.73%
3 2025-11-21 — 2.23% —

Full EPSS history (27 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-44847

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/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:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2021-44847

OS Trackers for CVE-2021-44847

vendor priority summary link
debian not yet assigned CVE-2021-44847 not yet assigned priority: Debian including 1 source packages (libtoxcore), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2021-44847
gentoo normal CVE-2021-44847: 1 GLSA(s) (202403-01), 1 atom(s) (net-libs/tox); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-44847
ubuntu medium CVE-2021-44847 medium priority: Ubuntu including 1 source packages (libtoxcore), 15 status rows across 15 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): released 9, ignored 4, DNE 1, needed 1. https://ubuntu.com/security/CVE-2021-44847

Affected software / configurations for CVE-2021-44847

Vendor Product Version Raw CPE
toktok toxcore >= 0.1.9, <= 0.1.11 cpe:2.3:a:toktok:toxcore:*:*:*:*:*:*:*:*
toktok toxcore >= 0.2.0, <= 0.2.12 cpe:2.3:a:toktok:toxcore:*:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
fedoraproject fedora 35 cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*

References for CVE-2021-44847

cvelogic Threat Intelligence