CVE-2020-18454: Cross Site Request Forgery (CSRF) vulnerability in bycms v1.3 via admin.php/systems/index/module_id/70/group_i

Routine

MEDIUM 6.8DOWNGRADE

CVE-2020-18454 is a medium-severity flaw (CVSS 6.8) affecting bycms. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Cross Site Request Forgery (CSRF) vulnerability in bycms v1.3 via admin.php/systems/index/module_id/70/group_id/1.html.

Why this priority

Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	6.8 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	Required
EPSS exploit chance	0.5% (top 59%)
CISA exploited list	No
Weakness	CWE-352
Published	2021-08-12
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: bycms project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-08-12 18:15 UTCPublished CVE record published
2026-06-17 02:59 UTCUpdated Record last modified

bycms project bycms DOWNGRADE

Affected: 1.3.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.3.0

1. Check installed version

apt-cache policy bycms || rpm -q bycms || bycms --version

2. No fixed release: DOWNGRADE to a release before 1.3.0 (Debian / Ubuntu)

apt-cache madison bycms sudo apt install bycms=<VERSION_BEFORE_1.3.0> sudo apt-mark hold bycms

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list bycms sudo dnf downgrade bycms-<VERSION_BEFORE_1.3.0> sudo dnf versionlock add bycms

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-18454?

bycms: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-18454 being exploited?

CVE-2020-18454 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2020-18454 affect?

CVE-2020-18454 affects bycms. Severity is medium (CVSS 6.8). Cross Site Request Forgery (CSRF) vulnerability in bycms v1.3 via admin.php/systems/index/module_id/70/group_id/1.html.

How urgent is CVE-2020-18454?

Priority 39/100. Public exploit reference

Software pages

PHP vulnerabilities

Related CVEs

CVE-2020-18457 MEDIUM 6.8 DOWNGRADE Cross Site Request Forgery (CSRF) vulnerability exists in bycms v1.3.0 that can add an admin account via admin
CVE-2020-18455 MEDIUM 4.8 DOWNGRADE Cross Site Scripting (XSS) vulnerability exists in bycms v3.0.4 via the title parameter in the edit function i

References

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