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7 ZipApplication

CVE-2024-11477

HIGH · 7.8 CVSS v3.1 Published 2024-11-22
Fix available
A fix is available. Upgrade to 24.07 or later.
See remediation →
81/100
Remediation priority · High
No privileges

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
7-Zip Zstandard Decompression Integer Underflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. Interaction with this library is required to exploit this vulnerability but attack vectors may vary depending on the implementation. The specific flaw exists within the implementation of Zstandard decompression. The issue results from the lack of proper validation of user-supplied data, which can result in an integer underflow before writing to memory. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-24346.

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 integer underflow vulnerability exists in 7-Zip's Zstandard decompression implementation due to insufficient validation of user-supplied data. This flaw allows an attacker to write beyond buffer boundaries during decompression, enabling arbitrary code execution in the context of the current process when a user opens a specially crafted Zstandard-compressed file.

MitigationUsers should avoid opening untrusted Zstandard-compressed files until 7-Zip is updated to a patched version. Organizations should inventory all deployments of 7-Zip and any applications embedding the 7-Zip library to ensure timely patching.

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
7 ZipApplication
Affected:< 24.07

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
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/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. Identify installed 7-Zip version
    Open 7-Zip File Manager, click Help > About, or right-click 7z.exe > Properties > Details to view the version number. Also check C:\Program Files\7-Zip\7z.exe or C:\Program Files (x86)\7-Zip\7z.exe if installed there.
    Affected if Version displayed is below 24.07 (for example, 24.06, 24.05, 23.x, or earlier)
  2. Confirm Zstandard codec is available
    Open 7-Zip File Manager, click Tools > Options > Plugins/Codecs tab, or attempt to compress/decompress a .zst file to verify Zstandard support is present in the installation.
    Affected if Zstandard (.zst) compression or decompression is supported and functional in the installed 7-Zip version
  3. Check for embedded 7-Zip libraries in custom applications
    Search for 7z.dll or 7zfx.dll files in application directories (use: dir /s C:\ 7z.dll 2>nul or PowerShell: Get-ChildItem -Path C:\ -Filter 7z*.dll -Recurse -ErrorAction SilentlyContinue). Review any found DLL file properties for version information.
    Affected if Any 7z.dll or 7zfx.dll file found is version 24.07 or later; if older or version cannot be determined, the embedding application may be affected

You are affected if 7-Zip version is below 24.07 AND Zstandard compression support is enabled or used in your environment.

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.

dbcve · scoped
Upgrade available Upgrade to 24.07 or later
Fixed in 24.07
Interim mitigation

Users should avoid opening untrusted Zstandard-compressed files until 7-Zip is updated to a patched version. Organizations should inventory all deployments of 7-Zip and any applications embedding the 7-Zip library to ensure timely patching.

Recommended fix High confidence

7-Zip 24.07 or later

  1. 1. Download the latest version of 7-Zip from the official website (https://www.7-zip.org/)
  2. 2. Verify you are downloading from the official 7-Zip website to avoid malicious alternatives
  3. 3. Install or update to version 24.07 or later
  4. 4. After installation, verify the version by opening 7-Zip File Manager and checking Help > About 7-Zip to confirm the installed version is 24.07 or higher

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in 7 Zip Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,120
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,392.

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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-2024-11477 in production — separate from our analysis above.

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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