CVE-2020-27788

Exp

An out-of-bounds read access vulnerability was discovered in UPX in PackLinuxElf64::canPack() function of p_lx_elf.cpp file. An attacker with a crafted input file could trigger this issue that could cause a crash leading to a denial of service.

Published: 2022-08-18 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-27788 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.32%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2020-27788

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2020-27788

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.05% 0.32% +0.27%
2 2025-08-24 0.14% 0.05% -0.09%
3 2025-08-20 — 0.14% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-27788

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]

Weakness enumeration for CVE-2020-27788

OS Trackers for CVE-2020-27788

vendor priority summary link
debian unimportant CVE-2020-27788 unimportant priority: Debian including 1 source packages (upx-ucl), 4 status rows across 4 suites (bullseye, forky, sid, trixie): resolved 4. https://security-tracker.debian.org/tracker/CVE-2020-27788
ubuntu low CVE-2020-27788 low priority: Ubuntu including 1 source packages (upx-ucl), 13 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 8, needs-triage 3, ignored 1, released 1. https://ubuntu.com/security/CVE-2020-27788

Affected software / configurations for CVE-2020-27788

Vendor Product Version Raw CPE
upx upx < 3.96 cpe:2.3:a:upx:upx:*:*:*:*:*:*:*:*

References for CVE-2020-27788

URL Tags
https://github.com/upx/upx/commit/1bb93d4fce9f1d764ba57bf5ac154af515b3fc83 Patch Third Party Advisory
https://github.com/upx/upx/issues/332 Exploit Issue Tracking Patch Third Party Advisory
cvelogic Threat Intelligence