PackLinuxElf64::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
PackLinuxElf64::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 a malware scanner to operate on the entire original data, or possibly have unspecified other impact via a crafted file.
- Published
- May 18, 2018
- Updated
- Jun 16, 2026
- EPSS
- 2.4% · 84th percentile
- CWE
- CWE-415
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Report tools
Action score
32
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.4%
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| 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 upx3.95
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 1.03+repack-5 | 1.03+repack-5 |
| openSUSE:Leap 15.1 | ucl | before 1.03-lp151.3.3.1 | 1.03-lp151.3.3.1 |
| openSUSE:Leap 15.1 | upx | before 3.96-lp151.3.3.1 | 3.96-lp151.3.3.1 |
| openSUSE:Tumbleweed | ucl | before 1.03-4.9 | 1.03-4.9 |
| openSUSE:Tumbleweed | upx | before 3.96-3.2 | 3.96-3.2 |
| SUSE:Package Hub 15 SP1 | ucl | before 1.03-bp151.4.3.1 | 1.03-bp151.4.3.1 |
| SUSE:Package Hub 15 SP1 | upx | before 3.96-bp151.4.3.1 | 3.96-bp151.4.3.1 |
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-2020-27801A heap-based buffer over-read was discovered in the get_le64 function in bele.h in UPX 4.0.0 via a crafted Mach-O file.31Monitor
- CVE-2020-27800A heap-based buffer over-read was discovered in the get_le32 function in bele.h in UPX 4.0.0 via a crafted Mach-O file.31Monitor
- CVE-2020-27799A heap-based buffer over-read was discovered in the acc_ua_get_be32 function in miniacc.h in UPX 4.0.0 via a crafted Mach-O file.31Monitor
- CVE-2020-27796A heap-based buffer over-read was discovered in the invert_pt_dynamic function in p_lx_elf.cpp in UPX 4.0.0 via a crafted Mach-O file.31Monitor
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 | 1.03+repack-5 · Debian:13 | Package registry (OSV) |
| opensuse:ucl | 1.03-lp151.3.3.1 · openSUSE:Leap 15.1 | Package registry (OSV) |
| opensuse:upx | 3.96-lp151.3.3.1 · openSUSE:Leap 15.1 | Package registry (OSV) |
| suse:ucl | 1.03-bp151.4.3.1 · SUSE:Package Hub 15 SP1 | Package registry (OSV) |
| suse:upx | 3.96-bp151.4.3.1 · SUSE:Package Hub 15 SP1 | 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.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
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.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-415 · Double FreeCVSS vector
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- lists.opensuse.org/opensuse-security-announce/2020-02/msg00001.html
- lists.opensuse.org/opensuse-security-announce/2020-02/msg00003.html
- lists.opensuse.org/opensuse-security-announce/2020-02/msg00007.html
- lists.opensuse.org/opensuse-security-announce/2020-02/msg00008.html
- github.com/upx/upx/blob/devel/NEWS
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/D7XU42G6MUQQXHWRP7DCF2JSIBOJ5GOO/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EUTVSTXAFTD552NO2K2RIF6MDQEHP3BE/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.