Vulnerability · Published Mar 26, 2021 · Assigned by redhat
CVE-2021-20285
Medium 6.6
In plain English
A medium-severity memory corruption in upx. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 55% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)6.6Medium
Exploit odds (30 days)0.8%top 44.8% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause a denial of service (SEGV or buffer overflow and application crash) or possibly have unspecified other impacts via a crafted ELF. The highest threat from this vulnerability is to system availability.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | upx | 3.96-r1 | ALPINE-CVE-2021-20285 |
| Alpine:v3.21 | upx | 3.96-r1 | ALPINE-CVE-2021-20285 |
| Alpine:v3.22 | upx | 3.96-r1 | ALPINE-CVE-2021-20285 |
| Alpine:v3.23 | upx | 3.96-r1 | ALPINE-CVE-2021-20285 |
| Alpine:v3.24 | upx | 3.96-r1 | ALPINE-CVE-2021-20285 |
| Debian:13 | upx-ucl | 4.2.2-1 | DEBIAN-CVE-2021-20285 |
| Debian:14 | upx-ucl | 4.2.2-1 | DEBIAN-CVE-2021-20285 |
| Ubuntu:22.04:LTS | upx-ucl | no fix listed | UBUNTU-CVE-2021-20285 |
| Ubuntu:24.04:LTS | upx-ucl | no fix listed | UBUNTU-CVE-2021-20285 |
| Ubuntu:25.10 | upx-ucl | no fix listed | UBUNTU-CVE-2021-20285 |
| Ubuntu:26.04:LTS | upx-ucl | no fix listed | UBUNTU-CVE-2021-20285 |
| Ubuntu:26.10 | upx-ucl | no fix listed | UBUNTU-CVE-2021-20285 |
Affected products (as reported)
Weakness: CWE-119
References
- https://github.com/upx/upx/issues/421 x_refsource_MISC
- https://bugzilla.redhat.com/show_bug.cgi?id=1937787 x_refsource_MISC