CVE-2021-27522: Learnsite 1.2.5.0 contains a remote privilege escalation vulnerability in /Manager/index.aspx through the Judg

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HIGH 8.8DOWNGRADE

CVE-2021-27522 is a high-severity flaw (CVSS 8.8) affecting learnsite. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Learnsite 1.2.5.0 contains a remote privilege escalation vulnerability in /Manager/index.aspx through the JudgIsAdmin() function. By modifying the initial letter of the key of a user cookie, the key of the administrator cookie can be obtained.

Why this priority

High severity
Public exploit reference

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

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	1.1% (top 33%)
CISA exploited list	No
Weakness	CWE-287
Published	2021-04-08
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: learnsite project

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

Am I affected?

Timeline

2021-04-08 16:15 UTCPublished CVE record published
2026-06-17 03:45 UTCUpdated Record last modified

learnsite project learnsite DOWNGRADE

Affected: 1.2.5.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.2.5.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.2.5.0 (Debian / Ubuntu)

apt-cache madison learnsite sudo apt install learnsite=<VERSION_BEFORE_1.2.5.0> sudo apt-mark hold learnsite

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

dnf --showduplicates list learnsite sudo dnf downgrade learnsite-<VERSION_BEFORE_1.2.5.0> sudo dnf versionlock add learnsite

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-2021-27522?

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

Is CVE-2021-27522 being exploited?

CVE-2021-27522 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-2021-27522 affect?

CVE-2021-27522 affects learnsite. Severity is high (CVSS 8.8). Learnsite 1.2.5.0 contains a remote privilege escalation vulnerability in /Manager/index.aspx through the JudgIsAdmin() function. By modifying the initial letter of the key of a user cookie, the key of the administrator cookie can be obtain

How urgent is CVE-2021-27522?

Priority 53/100. High severity; Public exploit reference

References

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