CVE-2011-4350: Yaws 1.91 has a directory traversal vulnerability in the way certain URLs are processed

This week

MEDIUM 6.5WATCHLISTDOWNGRADEMITIGATE

CVE-2011-4350 is a medium-severity flaw (CVSS 6.5) affecting yaws, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Yaws 1.91 has a directory traversal vulnerability in the way certain URLs are processed. A remote authenticated user could use this flaw to obtain content of arbitrary local files via specially-crafted URL request.

Why this priority

EPSS top 3%: very likely to be exploited
Public exploit reference
On your watchlist

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

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	16.1% (top 3%)
CISA exploited list	No
Weakness	CWE-22
Published	2019-11-26
Last modified	2026-06-16

Publisher (CNA): Red Hat, Inc. · Vendor: debian · yaws

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

Am I affected?

Timeline

2019-11-26 05:15 UTCPublished CVE record published
2026-06-16 23:34 UTCUpdated Record last modified

yaws yaws DOWNGRADE

Affected: 1.91

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.91

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 1.91 (Debian / Ubuntu)

apt-cache madison yaws sudo apt install yaws=<VERSION_BEFORE_1.91> sudo apt-mark hold yaws

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

dnf --showduplicates list yaws sudo dnf downgrade yaws-<VERSION_BEFORE_1.91> sudo dnf versionlock add yaws

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.

debian debian linux MITIGATE

Affected: 8.0 · 9.0 · 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Metasploit: Yaws Web Server Directory Traversal

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-2011-4350?

yaws: downgrade or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2011-4350 being exploited?

CVE-2011-4350 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-2011-4350 affect?

CVE-2011-4350 affects yaws, debian linux. Severity is medium (CVSS 6.5). Yaws 1.91 has a directory traversal vulnerability in the way certain URLs are processed. A remote authenticated user could use this flaw to obtain content of arbitrary local files via specially-crafted URL request.

How urgent is CVE-2011-4350?

Priority 57/100. EPSS top 3%: very likely to be exploited; Public exploit reference; On your watchlist

Software pages

Debian vulnerabilities

Related CVEs

CVE-2020-24916 CRITICAL 9.8 UPGRADE MITIGATE CGI implementation in Yaws web server versions 1.81 to 2.0.7 is vulnerable to OS command injection.
CVE-2020-24379 CRITICAL 9.8 UPGRADE MITIGATE WebDAV implementation in Yaws web server versions 1.81 to 2.0.7 is vulnerable to XXE injection.
CVE-2020-12872 MEDIUM 5.5 UPGRADE yaws_config.erl in Yaws through 2.0.2 and/or 2.0.7 loads obsolete TLS ciphers, as demonstrated by ones that al
CVE-2017-10974 HIGH 7.5 DOWNGRADE Yaws 1.91 allows Unauthenticated Remote File Disclosure via HTTP Directory Traversal with /%5C../ to port 8080
CVE-2016-1000108 MEDIUM 6.1 UPGRADE MITIGATE yaws before 2.0.4 does not attempt to address RFC 3875 section 4.1.18 namespace conflicts and therefore does n

References

← Back to latest CVEs