CVE-2025-2849: UPX p_lx_elf.cpp un_DT_INIT heap-based overflow
Noroxi assessment
Priority: Monitor (action score 19/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.30% (FIRST EPSS).
- Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: upx-ucl (Debian:13) 4.2.4-1.1; upx (openSUSE:Tumbleweed) 5.0.0-2.1.
Low priority for now. Upgrade to upx-ucl (Debian:13) 4.2.4-1.1; upx (openSUSE:Tumbleweed) 5.0.0-2.1 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
A vulnerability, which was classified as problematic, was found in UPX up to 5.0.0. Affected is the function PackLinuxElf64::un_DT_INIT of the file src/p_lx_elf.cpp. The manipulation leads to heap-based buffer overflow. It is possible to launch the attack on the local host. The exploit has been disclosed to the public and may be used. The patch is identified as e0b6ff192412f5bb5364c1948f4f6b27a0cd5ea2. It is recommended to apply a patch to fix this issue.
- Published
- Mar 27, 2025
- Updated
- Jun 17, 2026
- EPSS
- 0.3% · 23th percentile
- CWE
- CWE-119
Report tools
Action score
19
Monitor
Low priority for now.
- CVSS
- 19 / 40 · 4.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · VulDB
- 4.8
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| upx | upx | cpe:2.3:a:upx:upx |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- upx upxup to 5.0.0 inclusive
Versions reported by the vendor
Affected version ranges reported by the assigning authority (VulDB). Independent of NVD's CPE analysis and usually ahead of it.
n/a UPX
- 5.0affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:13 | upx-ucl | before 4.2.4-1.1 | 4.2.4-1.1 |
| openSUSE:Tumbleweed | upx | before 5.0.0-2.1 | 5.0.0-2.1 |
Same product
upx: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-3209UPX bele.h get_ne64 heap-based overflow39Monitor
- CVE-2019-14296canUnpack in p_vmlinx.cpp in UPX 3.95 allows remote attackers to cause a denial of service (SEGV or buffer overflow, and application crash) 32Monitor
- CVE-2018-11243PackLinuxElf64::unpack in p_lx_elf.cpp in UPX 3.95 allows remote attackers to cause a denial of service (double free), limit the ability of 32Monitor
Published before and after this one in the same product
- ← EarlierCVE-2021-43316Mar 24, 2023 · A heap-based buffer overflow was discovered in upx, during the generic pointer 'p' points to an inaccessible address in func get_le64().30Monitor
- ← EarlierCVE-2021-43317Mar 24, 2023 · A heap-based buffer overflows was discovered in upx, during the generic pointer 'p' points to an inaccessible address in func get_le32().30Monitor
- ← EarlierCVE-2021-46179Aug 22, 2023 · Reachable Assertion vulnerability in upx before 4.0.0 allows attackers to cause a denial of service via crafted file passed to the the readx26Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:upx-ucl | 4.2.4-1.1 · Debian:13 | Package registry (OSV) |
| opensuse:upx | 5.0.0-2.1 · openSUSE:Tumbleweed | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
No history yet (it accumulates with the daily EPSS job).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory BufferCVSS vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Overflow BuffersCAPEC-100likelihood: High · Very High
- Buffer ManipulationCAPEC-123likelihood: High · Very High
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
- Filter Failure through Buffer OverflowCAPEC-24likelihood: High · High
- MIME ConversionCAPEC-42likelihood: High · High
- Overflow Binary Resource FileCAPEC-44likelihood: High · Very High
- Buffer Overflow via Symbolic LinksCAPEC-45likelihood: High · High
ATT&CK techniques
—
Change log
- Fix✗ → ✓
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References
Show all references (4 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.