CVE-2018-0542: Directory traversal vulnerability in WebProxy version 1.7.8 allows an attacker to read arbitrary files via uns

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HIGH 7.5REMOTEDOWNGRADE

CVE-2018-0542 is a high-severity flaw (CVSS 7.5) affecting webproxy. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Directory traversal vulnerability in WebProxy version 1.7.8 allows an attacker to read arbitrary files via unspecified vectors.

Why this priority

High severity
Remotely exploitable, no login, no user action

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

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.2% (top 17%)
CISA exploited list	No
Weakness	CWE-22
Published	2018-03-22
Last modified	2026-06-17

Publisher (CNA): JPCERT/CC · Vendor: webproxy project

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

Am I affected?

Timeline

2018-03-22 13:29 UTCPublished CVE record published
2026-06-17 01:31 UTCUpdated Record last modified

webproxy project webproxy DOWNGRADE

Affected: 1.7.8

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.7.8

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.7.8 (Debian / Ubuntu)

apt-cache madison webproxy sudo apt install webproxy=<VERSION_BEFORE_1.7.8> sudo apt-mark hold webproxy

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

dnf --showduplicates list webproxy sudo dnf downgrade webproxy-<VERSION_BEFORE_1.7.8> sudo dnf versionlock add webproxy

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-2018-0542?

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

Is CVE-2018-0542 being exploited?

CVE-2018-0542 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-2018-0542 affect?

CVE-2018-0542 affects webproxy. Severity is high (CVSS 7.5). Directory traversal vulnerability in WebProxy version 1.7.8 allows an attacker to read arbitrary files via unspecified vectors.

How urgent is CVE-2018-0542?

Priority 52/100. High severity; Remotely exploitable, no login, no user action

References

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