CVE-2018-20595: A CSRF issue was discovered in web/authorization/oauth2/controller/OAuth2ClientController.java in hsweb 3.0.4

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HIGH 8.8DOWNGRADE

CVE-2018-20595 is a high-severity flaw (CVSS 8.8) affecting hsweb. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A CSRF issue was discovered in web/authorization/oauth2/controller/OAuth2ClientController.java in hsweb 3.0.4 because the state parameter in the request is not compared with the state parameter in the session after user authentication is successful.

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	None
User interaction	Required
EPSS exploit chance	0.6% (top 49%)
CISA exploited list	No
Weakness	CWE-352
Published	2018-12-30
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: hsweb

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

Am I affected?

Timeline

2018-12-30 18:29 UTCPublished CVE record published
2026-06-17 01:53 UTCUpdated Record last modified

hsweb hsweb DOWNGRADE

Affected: 3.0.4

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.0.4

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 3.0.4 (Debian / Ubuntu)

apt-cache madison hsweb sudo apt install hsweb=<VERSION_BEFORE_3.0.4> sudo apt-mark hold hsweb

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

dnf --showduplicates list hsweb sudo dnf downgrade hsweb-<VERSION_BEFORE_3.0.4> sudo dnf versionlock add hsweb

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-2018-20595?

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

Is CVE-2018-20595 being exploited?

CVE-2018-20595 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-2018-20595 affect?

CVE-2018-20595 affects hsweb. Severity is high (CVSS 8.8). A CSRF issue was discovered in web/authorization/oauth2/controller/OAuth2ClientController.java in hsweb 3.0.4 because the state parameter in the request is not compared with the state parameter in the session after user authentication is su

How urgent is CVE-2018-20595?

Priority 49/100. High severity; Public exploit reference

Software pages

Java vulnerabilities

Related CVEs

CVE-2018-20594 MEDIUM 6.1 DOWNGRADE An issue was discovered in hsweb 3.0.4

References

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