CVE-2021-40595: SQL injection vulnerability in Sourcecodester Online Leave Management System v1 by oretnom23, allows attackers

This week

CRITICAL 9.8REMOTEDOWNGRADE

CVE-2021-40595 is a critical-severity flaw (CVSS 9.8) affecting online leave management system. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

SQL injection vulnerability in Sourcecodester Online Leave Management System v1 by oretnom23, allows attackers to execute arbitrary SQL commands via the username parameter to /leave_system/classes/Login.php.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

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

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.4% (top 28%)
CISA exploited list	No
Weakness	CWE-89
Published	2022-01-21
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: online leave 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

2022-01-21 20:15 UTCPublished CVE record published
2026-06-17 04:07 UTCUpdated Record last modified

online leave management system project online leave management system DOWNGRADE

Affected: 1.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0

1. Check installed version

apt-cache policy online-leave-management-system || rpm -q online-leave-management-system || online-leave-management-system --version

2. No fixed release: DOWNGRADE to a release before 1.0 (Debian / Ubuntu)

apt-cache madison online-leave-management-system sudo apt install online-leave-management-system=<VERSION_BEFORE_1.0> sudo apt-mark hold online-leave-management-system

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

dnf --showduplicates list online-leave-management-system sudo dnf downgrade online-leave-management-system-<VERSION_BEFORE_1.0> sudo dnf versionlock add online-leave-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-2021-40595?

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

Is CVE-2021-40595 being exploited?

CVE-2021-40595 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-2021-40595 affect?

CVE-2021-40595 affects online leave management system. Severity is critical (CVSS 9.8). SQL injection vulnerability in Sourcecodester Online Leave Management System v1 by oretnom23, allows attackers to execute arbitrary SQL commands via the username parameter to /leave_system/classes/Login.php.

How urgent is CVE-2021-40595?

Priority 62/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Software pages

PHP vulnerabilities

Related CVEs

CVE-2022-45009 HIGH 7.2 DOWNGRADE Online Leave Management System v1.0 was discovered to contain an arbitrary file upload vulnerability at /leave
CVE-2022-45008 MEDIUM 4.8 DOWNGRADE Online Leave Management System v1.0 was discovered to contain a stored cross-site scripting (XSS) vulnerabilit
CVE-2022-43179 HIGH 7.2 DOWNGRADE Online Leave Management System v1.0 was discovered to contain a SQL injection vulnerability via the component
CVE-2022-41379 HIGH 7.2 DOWNGRADE An arbitrary file upload vulnerability in the component /leave_system/classes/Users.php?f=save of Online Leave
CVE-2022-41355 HIGH 7.2 DOWNGRADE Online Leave Management System v1.0 was discovered to contain a SQL injection vulnerability via the id paramet

References

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