CVE-2022-4899Network attack vector

CLI interruption via empty output-directory argument

Published Mar 31, 2023 · Updated Feb 18, 2025

Buffer underflow in Meta Platforms, Inc. Zstandard before 1.5.4 allows attackers to interrupt the zstd CLI via an empty output-directory argument. In programs/util.c, mallocAndJoin2Dir points at the start of a newly allocated output-directory buffer and then reads one byte before it when dir1 is empty. An empty value for --output-dir-flat or --output-dir-mirror reaches the flaw; reachability requires control of CLI arguments or an application that forwards them.

CVSS severity7.5
High
EPSS probability1.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer underflow in Meta Platforms, Inc. Zstandard before 1.5.4 allows attackers to interrupt the zstd CLI via an empty output-directory argument. In programs/util.c, mallocAndJoin2Dir points at the start of a newly allocated output-directory buffer and then reads one byte before it when dir1 is empty. An empty value for --output-dir-flat or --output-dir-mirror reaches the flaw; reachability requires control of CLI arguments or an application that forwards them.

The record

CVE
CVE-2022-4899
Published
Mar 31, 2023
Updated
Feb 18, 2025
Vendor
Meta Platforms, Inc.
Product
Zstandard
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 31, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 18, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=zstd 1.5.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Meta Platforms, Inc. · Zstandardversion=zstd 1.5.4

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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