CVE-2021-27921: fedoraproject fedora Improper Input Validation
CVSS: 7.5v3.1HighModified
AliasesALPINE-CVE-2021-27921GHSA-f4w8-cv6p-x6r5BIT-pillow-2021-27921PYSEC-2021-40UBUNTU-CVE-2021-27921DEBIAN-CVE-2021-27921
Published 03-03-2021Last modified 15-08-2025
Vulnerability summary
CVE-2021-27921 is a high (CVSS 7.5) Improper Input Validation vulnerability in fedoraproject fedora. EPSS estimates a 3.17% chance of exploitation in the next 30 days, higher than 87.8% of scored vulnerabilities.
CVSS score
7.5/10
010
High · v3.1 (NVD)EPSS score
3.17%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 9 · Related 8Timeline
- 03-03-2021PublishedVulnerability first disclosed.
- 15-08-2025Last modifiedVulnerability information updated.
Description
Pillow before 8.1.2 allows attackers to cause a denial of service (memory consumption) because the reported size of a contained image is not properly checked for a BLP container, and thus an attempted memory allocation can be very large.
CVSS metrics
7 scores · 5 sources · 3 versionsHigh 8.7Preferred score · OSV · Pypi (Ecosystem advisory) · calculated from vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NSourcesSingle source
High 7.5Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSourcesAll 5 agree
- OSV · AlpineEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · PypiEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Medium 5.0Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:N/I:N/A:PSourcesSingle source
EPSS trend
Probability
3.17%
Chance of exploitation in the next 30 days
Percentile
88%
Versus all other CVEs
30-day change
0.00 pp
From 3.17% on 18-09-2026
18-09-202618-10-2026
EPSS score3.17%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu2 products
- pillow< 5.1.0-1ubuntu0.5 | < 7.0.0-4ubuntu0.3
- pillow-python2All versions (No fix recorded)
Alpine1 product
- py3-pillow< 8.1.2-r0
Debian1 product
- pillow< 8.1.2-1
Fedoraproject1 product
- fedoraEOL32 | 33 | 34
PyPI1 product
- pillow< 8.1.2 | < 8.1.1
Python1 product
- pillow< 8.1.1
6 vendors · 7 products
References
25 links- pillow.readthedocs.io/en/stable/releasenotes/8.1.1.htmlX Refsource MISCX TransferredWEBREPORTRelease NotesVendor Advisory
