CVE-2021-28678: Pillow Insufficient Verification Of Data Authenticity Vulnerability

MODERATE
Advisory Identifier: GHSA-hjfx-8p6c-g7gx
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CVSS 5.5
CWE-345
Published
Advisory Summary

CVE-2021-28678 is a MODERATE (CVSS 5.5) insufficient verification of data authenticity vulnerability (CWE-345: Insufficient Verification of Data Authenticity) affecting Pillow libraries in the PyPI ecosystem. The issue involves insufficient verification of data authenticity in pillow. Remediation is available by upgrading affected packages to version 8.2.0.

CVE-2021-28678 at a Glance

CVE Identifier CVE-2021-28678
GHSA Identifier GHSA-hjfx-8p6c-g7gx
Severity MODERATE
CVSS v3.1 Base Score 5.5
CWE Classification CWE-345: Insufficient Verification of Data Authenticity
Affected Product Pillow
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 5.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2021-28678

To remediate this vulnerability, upgrade all affected Pillow dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Pillow fixed: 8.2.0 
pip install Pillow>=8.2.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show Pillow

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2021-28678, inspect your installed packages using pip:

pip show Pillow

Analyze the terminal output to locate any version of Pillow in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 8.2.0), your application is affected.

Note: The pip show Pillow command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-345: Insufficient Verification of Data Authenticity, where the product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. In Pillow, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

An issue was discovered in Pillow before 8.2.0. For BLP data, BlpImagePlugin did not properly check that reads (after jumping to file offsets) returned data. This could lead to a DoS where the decoder could be run a large number of times on empty data.

CVE-2021-28678 Affected Pillow Versions

1 component(s)
Fixed Versions:
8.2.0
Product / Package Ecosystem Affected Versions Fixed Version
Pillow
pypi/Pillow
PyPI
≥ 5.1.0
< 8.2.0
8.2.0

References

NVD — CVE-2021-28678 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-28678
Pillow Source Repository REPOSITORY
https://github.com/python-pillow/Pillow/pull/5377
Pillow Source Repository REPOSITORY
https://github.com/python-pillow/Pillow/pull/5377/commits/496245aa4365d0827390bd0b6fbd11287453b3a1
GitHub Advisory / Wiki ADVISORY
https://github.com/advisories/GHSA-hjfx-8p6c-g7gx
Pillow Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/pillow/PYSEC-2021-94.yaml
Pillow Source Repository REPOSITORY
https://github.com/python-pillow/Pillow
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MQHA5HAIBOYI3R6HDWCLAGFTIQP767FL
Pillow Release RELEASE
https://pillow.readthedocs.io/en/stable/releasenotes/8.2.0.html#cve-2021-28678-fix-blp-dos
Pillow Security Information SECURITY
https://security.gentoo.org/glsa/202107-33

Frequently Asked Questions

What is CVE-2021-28678?
CVE-2021-28678 is a security vulnerability in Pillow involving Insufficient Verification of Data Authenticity in Pillow under CWE-345: Insufficient Verification of Data Authenticity.
Which Pillow versions are affected?
Affected versions include releases prior to 8.2.0 across affected packages: Pillow.
What version fixes CVE-2021-28678?
Upgrading to 8.2.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is Pillow affected?
Yes, Pillow is affected in releases prior to 8.2.0. Upgrade your dependency to 8.2.0 or later.
What is the CVSS score of CVE-2021-28678?
CVE-2021-28678 has a CVSS v3.1 base score of 5.5 (MODERATE) with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2021-28678?
CVE-2021-28678 is classified under CWE-345: Insufficient Verification of Data Authenticity (The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.).
How can I check PyPI dependencies for CVE-2021-28678?
Run the dependency tree command: 'pip show Pillow'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hjfx-8p6c-g7gx",
  "modified" : "2024-10-14T21:36:39Z",
  "published" : "2021-06-08T18:49:20Z",
  "aliases" : [ "CVE-2021-28678" ],
  "summary" : "Insufficient Verification of Data Authenticity in Pillow",
  "details" : "An issue was discovered in Pillow before 8.2.0. For BLP data, BlpImagePlugin did not properly check that reads (after jumping to file offsets) returned data. This could lead to a DoS where the decoder could be run a large number of times on empty data.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "Pillow"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.1.0"
      }, {
        "fixed" : "8.2.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-28678"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/python-pillow/Pillow/pull/5377"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/python-pillow/Pillow/pull/5377/commits/496245aa4365d0827390bd0b6fbd11287453b3a1"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-hjfx-8p6c-g7gx"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/pillow/PYSEC-2021-94.yaml"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/python-pillow/Pillow"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MQHA5HAIBOYI3R6HDWCLAGFTIQP767FL"
  }, {
    "type" : "WEB",
    "url" : "https://pillow.readthedocs.io/en/stable/releasenotes/8.2.0.html#cve-2021-28678-fix-blp-dos"
  }, {
    "type" : "WEB",
    "url" : "https://security.gentoo.org/glsa/202107-33"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-345" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-06-03T21:38:37Z",
    "nvd_published_at" : "2021-06-02T16:15:00Z"
  }
}