CVE-2025-2849Public exploit

Local crash via unchecked ELF header count

Published Mar 27, 2025 · Updated Mar 27, 2025

Heap-based buffer overflow in UPX 5.0.0 and earlier allows local users to crash the process by decompressing a crafted ELF file. PackLinuxElf64::un_DT_INIT trusts the ELF program-header count and iterates beyond its allocated low-memory buffer without validating the count. The attacker must cause UPX to unpack the crafted file; the demonstrated consequence is an out-of-bounds read and process termination, with no reported data disclosure or code execution.

CVSS severity5.5
Medium
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in UPX 5.0.0 and earlier allows local users to crash the process by decompressing a crafted ELF file. PackLinuxElf64::un_DT_INIT trusts the ELF program-header count and iterates beyond its allocated low-memory buffer without validating the count. The attacker must cause UPX to unpack the crafted file; the demonstrated consequence is an out-of-bounds read and process termination, with no reported data disclosure or code execution.

The record

CVE
CVE-2025-2849
Published
Mar 27, 2025
Updated
Mar 27, 2025
Vendor
The UPX Team
Product
UPX
Classifications
CWE-119, CWE-122, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 27, 2025CVE publishedPublication date reported by the CVE source.
  2. Mar 27, 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=5.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The UPX Team · UPXversion=5.0

Published CVSS scores

3.3VulDBCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
1.7VulDBAV:L/AC:L/Au:S/C:N/I:N/A:P
5.5NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
4.8VulDBCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-122Heap-based Buffer Overflow
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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