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PillowApplication · Python

CVE-2021-25293

HIGH · 7.5 CVSS v3.1 Published 2021-03-19
Fix available
A fix is available. Upgrade to 8.1.1 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An issue was discovered in Pillow before 8.1.1. There is an out-of-bounds read in SGIRleDecode.c.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

An out-of-bounds read vulnerability exists in the SGIRleDecode.c component of Pillow versions before 8.1.1, which handles decoding of SGI RLE (Run-Length Encoded) image files. The vulnerability could allow an attacker to cause a denial of service or potentially read sensitive memory contents by processing a specially crafted SGI image file.

MitigationUpgrade Pillow to version 8.1.1 or later to patch the out-of-bounds read vulnerability in the SGIRleDecode.c image decoder.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
PillowApplication
Affected:< 8.1.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Pillow version
    Run 'python -c "import PIL; print(PIL.__version__)"' or 'pip show pillow' to retrieve the installed Pillow version number
    Affected if Version is less than 8.1.1 (e.g., 8.1.0, 8.0.0, 7.x, etc.)
  2. Confirm Pillow is present
    Run 'python -c "import PIL"' without error, or check pip list for pillow package
    Affected if Pillow package is installed and importable
  3. Identify SGI RLE image processing
    Search codebase or logs for usage of PIL.Image.open() or Image.open() with .sgi or .rgb files, or search for 'SGI' in image loading code
    Affected if Application or workflow decodes SGI RLE formatted images using Pillow's SGIRleDecode decoder

You are affected if Pillow version is below 8.1.1 AND your environment processes SGI RLE (Run-Length Encoded) image files using Pillow.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to 8.1.1 or later
Fixed in 8.1.1
Interim mitigation

Upgrade Pillow to version 8.1.1 or later to patch the out-of-bounds read vulnerability in the SGIRleDecode.c image decoder.

Fix this in Pillow Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,520
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,432.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-25293 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data