CVE-2021-29663: CourseMS (aka Course Registration Management System) 2.1 is affected by cross-site scripting (XSS)

Routine

MEDIUM 4.8DOWNGRADE

CVE-2021-29663 is a medium-severity flaw (CVSS 4.8) affecting course registration management system. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

CourseMS (aka Course Registration Management System) 2.1 is affected by cross-site scripting (XSS). When an attacker with access to an Admin account creates a Job Title in the Site area (aka the admin/add_jobs.php name parameter), they can insert an XSS payload. This payload will execute whenever anyone visits the registration page.

Why this priority

Public exploit reference

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

Risk facts

CVSS score	4.8 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	Required
EPSS exploit chance	0.8% (top 43%)
CISA exploited list	No
Weakness	CWE-79
Published	2021-03-31
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: course registration management system project

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

Am I affected?

Timeline

2021-03-31 20:15 UTCPublished CVE record published
2026-06-17 03:48 UTCUpdated Record last modified

course registration management system project course registration management system DOWNGRADE

Affected: 2.1

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.1

1. Check installed version

apt-cache policy course-registration-management-system || rpm -q course-registration-management-system || course-registration-management-system --version

2. No fixed release: DOWNGRADE to a release before 2.1 (Debian / Ubuntu)

apt-cache madison course-registration-management-system sudo apt install course-registration-management-system=<VERSION_BEFORE_2.1> sudo apt-mark hold course-registration-management-system

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

dnf --showduplicates list course-registration-management-system sudo dnf downgrade course-registration-management-system-<VERSION_BEFORE_2.1> sudo dnf versionlock add course-registration-management-system

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-2021-29663?

course registration management system: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-29663 being exploited?

CVE-2021-29663 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-2021-29663 affect?

CVE-2021-29663 affects course registration management system. Severity is medium (CVSS 4.8). CourseMS (aka Course Registration Management System) 2.1 is affected by cross-site scripting (XSS). When an attacker with access to an Admin account creates a Job Title in the Site area (aka the admin/add_jobs.php name parameter), they can

How urgent is CVE-2021-29663?

Priority 36/100. Public exploit reference

Software pages

PHP vulnerabilities

References

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