CVE-2020-27304

Exp

The CivetWeb web library does not validate uploaded filepaths when running on an OS other than Windows, when using the built-in HTTP form-based file upload mechanism, via the mg_handle_form_request API. Web applications that use the file upload form handler, and use parts of the user-controlled filename in the output path, are susceptible to directory traversal

Published: 2021-10-21 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-27304 is rated High Exploit Risk (80.7/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 1.00%). 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-2020-27304

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

Exploit prediction scoring system (EPSS) score for CVE-2020-27304

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 2025-11-21 1.16% 1.00% -0.16%
2 2025-11-18 1.00% 1.16% +0.16%
3 2025-06-18 — 1.00% —

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-27304

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
7.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 6.4 [email protected]

Weakness enumeration for CVE-2020-27304

OS Trackers for CVE-2020-27304

vendor priority summary link
debian unimportant CVE-2020-27304 unimportant priority: Debian including 1 source packages (civetweb), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2020-27304
redhat high — https://access.redhat.com/security/cve/CVE-2020-27304
ubuntu medium CVE-2020-27304 medium priority: Ubuntu including 1 source packages (civetweb), 13 status rows across 13 suites (hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 9, needs-triage 4. https://ubuntu.com/security/CVE-2020-27304

Affected software / configurations for CVE-2020-27304

Vendor Product Version Raw CPE
civetweb_project civetweb >= 1.8, < 1.15 cpe:2.3:a:civetweb_project:civetweb:*:*:*:*:*:*:*:*
siemens sinec_infrastructure_network_services < 1.0.1.1 cpe:2.3:a:siemens:sinec_infrastructure_network_services:*:*:*:*:*:*:*:*

References for CVE-2020-27304

cvelogic Threat Intelligence