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CVE-2021-22564

Out of bounds Copy in Libjxl in large image groups

Public exploit available. Not confirmed exploited in the wild yet. A vendor fix is available.

CVSS 3.14.5MediumEPSS percentile23rd0.3% chance in 30 daysCISA KEVNot listedNo confirmed exploitation
Public exploit: 1 sourceFixVendor fixNo build named by the sources

Published Updated Sources: CVE.org, NVD

NVD CVE.org

What to do

The vendor has published a fix. Version details are below where the sources state them.

  • Google LLC libjxlAffected: ≥ unspecified, ≤ 0.6.0Upgrade to: after 0.6.0Stated by: CVE record
  • Libjxl Project LibjxlAffected: ≤ 0.6.0Upgrade to: after 0.6.0Stated by: NVD

Versions as the sources state them. Full version matrix after sign-in

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What it is

From the CVE record

For certain valid JPEG XL images with a size slightly larger than an integer number of groups (256x256 pixels) when processing the groups out of order the decoder can perform an out of bounds copy of image pixels from an image buffer in the heap to another. This copy can occur when processing the right or bottom edges of the image, but only when groups are processed in certain order. Groups can be processed out of order in multi-threaded decoding environments with heavy thread load but also with images that contain the groups in an arbitrary order in the file. It is recommended to upgrade past 0.6.0 or patch with https://github.com/libjxl/libjxl/pull/775

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS23rd
Public exploit
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

1 source with a proof of concept or module.

Exploit links, PoCs and Metasploit modules after sign-in
EPSS

0.3% chance of exploitation activity in the next 30 days, which ranks it in the 23rd percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

The patch came 471 days before any public exploit.

  1. Public exploit / PoCsource: github-poc
  2. Patch availablerecord updated
  3. Publishedweakness classified, att&ck mapped

Affected products

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

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

Scored 4.5 by NVD.

How it is reached

  • Attack Vector LocalRequires local access to the vulnerable system (e.g. local login, malicious file)
  • Attack Complexity HighRequires specific conditions like a race condition or non-default configuration
  • Privileges Required LowRequires basic user-level privileges
  • User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality LowSome restricted information is disclosed, but limited in scope
  • Integrity LowData modification is possible but limited in scope or consequence
  • Availability LowReduced performance or intermittent disruption of service

Weaknesses

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Sources

References in the record

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