CVE-2021-28021

Exp

Buffer overflow vulnerability in function stbi__extend_receive in stb_image.h in stb 2.26 via a crafted JPEG file.

Published: 2021-10-15 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-28021 is rated High Exploit Risk (71/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.33%). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.18% over the last day, indicating growing attacker interest. 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-2021-28021

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

Exploit prediction scoring system (EPSS) score for CVE-2021-28021

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 0.15% 1.33% +1.18%
2 2026-03-06 0.15% 0.15% +0.00%
3 2026-03-02 — 0.15% —

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-28021

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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: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.
 1.8 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/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:M)
Exploitation needs some favorable conditions, but not exceptional ones.
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.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2021-28021

OS Trackers for CVE-2021-28021

vendor priority summary link
debian not yet assigned CVE-2021-28021 not yet assigned priority: Debian including 1 source packages (libstb), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-28021
gentoo normal CVE-2021-28021: 1 GLSA(s) (202409-15), 1 atom(s) (dev-libs/stb); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-28021
redhat medium — https://access.redhat.com/security/cve/CVE-2021-28021
ubuntu medium CVE-2021-28021 medium priority: Ubuntu including 1 source packages (libstb), 14 status rows across 14 suites (focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 9, needs-triage 5. https://ubuntu.com/security/CVE-2021-28021

Affected software / configurations for CVE-2021-28021

Vendor Product Version Raw CPE
stb_project stb 2.26 cpe:2.3:a:stb_project:stb:2.26:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
fedoraproject fedora 35 cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

References for CVE-2021-28021

URL Tags
https://github.com/nothings/stb/issues/1108 Exploit Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/01/msg00045.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3TDGZFLBOP27LZKLH45WQLSNPSPP7S7Z/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AF2CNP4FVC6LDKNOO4WDCGNDYIP3MPK6/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BEGXBDEMTFGINETMJENBZ6SCHVEJQJSY/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/G2M5CRSGPRF7G3YB5CLU4FXW7ANNHAYT/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TXX76TJMZBPN3NU542MGN6B7C7QHRFGB/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VP2YEXEAJWI76FPM7D7VXHWD3WESQEYC/
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