CVE-2002-1857: jo! jo Webserver 1.0, when running on Windows, allows remote attackers to retrieve files in the WEB-INF direct

Routine

MEDIUM 5.0DOWNGRADE

CVE-2002-1857 is a medium-severity flaw (CVSS 5.0) affecting jo webserver. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

jo! jo Webserver 1.0, when running on Windows, allows remote attackers to retrieve files in the WEB-INF directory, which contains Java class files and configuration information, via a request to the WEB-INF directory with a trailing dot ("WEB-INF.").

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	2.1% (top 18%)
CISA exploited list	No
Published	2002-12-31
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: jo

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2002-12-31 05:00 UTCPublished CVE record published
2026-06-16 22:00 UTCUpdated Record last modified

jo jo webserver DOWNGRADE

Affected: 1.0_rc1

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.0_rc1

1. Check installed version

apt-cache policy jo-webserver || rpm -q jo-webserver || jo-webserver --version

2. No fixed release: DOWNGRADE to a release before 1.0_rc1 (Debian / Ubuntu)

apt-cache madison jo-webserver sudo apt install jo-webserver=<VERSION_BEFORE_1.0_rc1> sudo apt-mark hold jo-webserver

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

dnf --showduplicates list jo-webserver sudo dnf downgrade jo-webserver-<VERSION_BEFORE_1.0_rc1> sudo dnf versionlock add jo-webserver

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-2002-1857?

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

Is CVE-2002-1857 being exploited?

CVE-2002-1857 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-2002-1857 affect?

CVE-2002-1857 affects jo webserver. Severity is medium (CVSS 5.0). jo! jo Webserver 1.0, when running on Windows, allows remote attackers to retrieve files in the WEB-INF directory, which contains Java class files and configuration information, via a request to the WEB-INF directory with a trailing dot ("W

How urgent is CVE-2002-1857?

Priority 38/100. No elevated risk signals yet.

Software pages

Java vulnerabilities · Windows vulnerabilities

References

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