CVE-2021-34552

Pillow through 8.2.0 and PIL (aka Python Imaging Library) through 1.1.7 allow an attacker to pass controlled parameters directly into a convert function to trigger a buffer overflow in Convert.c.

Published: 2021-07-13 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-34552 is rated High Risk (69.3/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 3.16%). High exploitation likelihood—assess exposure and prioritize remediation.

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

Exploit prediction scoring system (EPSS) score for CVE-2021-34552

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 2026-06-23 3.25% 3.16% -0.09%
2 2026-06-15 0.34% 3.25% +2.91%
3 2025-12-28 — 0.34% —

Full EPSS history (26 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-34552

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-2021-34552

GitHub Security Advisory for CVE-2021-34552

OS Trackers for CVE-2021-34552

vendor priority summary link
alpine critical CVE-2021-34552: 1 source package rows (py3-pillow); 8 state rows across 8 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community, edge-main); fixed 8, open 0. https://security.alpinelinux.org/vuln/CVE-2021-34552
debian not yet assigned CVE-2021-34552 not yet assigned priority: Debian including 1 source packages (pillow), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-34552
gentoo high CVE-2021-34552: 1 GLSA(s) (202211-10), 1 atom(s) (dev-python/pillow); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-34552
redhat medium — https://access.redhat.com/security/cve/CVE-2021-34552
suse high CVE-2021-34552 severity important: SUSE including 28 source package names (python-Pillow, python-Pillow-2.8.1-4.25.1, …), 53 product×package rows across 21 product lines (HPE Helion OpenStack 8, SUSE Liberty Linux 8, … (21 product lines)): Fixed 32, Known Not Affected 21. https://www.suse.com/security/cve/CVE-2021-34552/
ubuntu low CVE-2021-34552 low priority: Ubuntu including 3 source packages (pillow, pillow-python2, python-imaging), 48 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 28, not-affected 9, released 6, needs-triage 3, ignored 2. https://ubuntu.com/security/CVE-2021-34552

Affected software / configurations for CVE-2021-34552

Vendor Product Version Raw CPE
python pillow >= 1.0, <= 1.1.7 cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:*
python pillow >= 1.2, <= 8.2.0 cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
fedoraproject fedora 33 cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

References for CVE-2021-34552

cvelogic Threat Intelligence