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CVE Record

CVE-2021-34552: Pillow through 8.2.0 and PIL (aka Python Imaging Library) through 1.1.7 allow an attacker to pass controlle...

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.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

Pillow and legacy PIL versions can hit a buffer overflow when controlled parameters reach an image conversion function. Services that process user-supplied images or conversion settings are the main concern. The source bundle does not provide CVSS, exploit details, or active exploitation evidence.

Executive priority

Treat this as a targeted dependency hygiene issue unless your business processes untrusted images at scale. Prioritize internet-facing upload, media, document, and automation services first, because they are more likely to expose image conversion paths.

Technical view

CVE-2021-34552 affects Pillow through 8.2.0 and PIL through 1.1.7. The reported flaw is a buffer overflow in Convert.c triggered by attacker-controlled parameters passed into a convert function. Pillow 8.3.0 release notes list a buffer overflow fix, and Linux distributions issued package updates.

Likely exposure

Exposure is most likely in Python applications, APIs, workers, or pipelines using Pillow or legacy PIL to transform images, especially where images or conversion parameters come from users, partners, or automated imports.

Exploitation context

The provided sources do not show CISA KEV listing or active exploitation. They describe a memory-safety issue and vendor or distribution updates, but not public weaponization, exploit prerequisites, or real-world incidents.

Researcher notes

Evidence is limited to the CVE description, Pillow release notes, and distribution advisories. No CVSS vector, CWE, exploit status, or precise affected call pattern beyond controlled convert parameters is provided in the bundle.

Mitigation direction

  • Upgrade Pillow to 8.3.0 or later where possible.
  • Apply Debian, Fedora, or Gentoo security updates for packaged Pillow builds.
  • Remove legacy PIL through 1.1.7 from supported environments.
  • Limit untrusted access to image conversion parameters.
  • Check vendor guidance before relying on unsupported workarounds.

Validation and detection

  • Inventory Python environments for Pillow and PIL versions.
  • Review dependency lockfiles, containers, and distro packages for vulnerable builds.
  • Confirm production images include the relevant security update.
  • Identify services processing untrusted images or conversion options.
  • Verify no legacy PIL package remains installed.
Prepared
Confidence
medium
Sources
7

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
7Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

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