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CVE-2011-4350· NVD / CVE Program· CNA redhat

Yaws 1.91 has a directory traversal vulnerability in the way certain URLs are processed.

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.

MediumCVSS 6.5 · v3.1—Weaponized Fix available
Published
Nov 26, 2019
Updated
Jun 16, 2026
EPSS
16.1% · 97th percentile
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Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
5 / 30 · 16.1%

Affected systems

VendorProduct
yawsyaws
debiandebian linux

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • debian debian linux10.0
  • debian debian linux8.0
  • debian debian linux9.0
  • yaws yaws1.91

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • yaws yaws

    • 1.91affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12yawsbefore 1.91-21.91-2

Same product

yaws: all records

Other highest-scoring records for the same primary product.

  • CVE-2017-10974Yaws 1.91 allows Unauthenticated Remote File Disclosure via HTTP Directory Traversal with /%5C../ to port 8080.
    54Plan
  • CVE-2020-24916CGI implementation in Yaws web server versions 1.81 to 2.0.7 is vulnerable to OS command injection.
    44Plan
  • CVE-2020-24379WebDAV implementation in Yaws web server versions 1.81 to 2.0.7 is vulnerable to XXE injection.
    40Plan
  • CVE-2016-1000108yaws before 2.0.4 does not attempt to address RFC 3875 section 4.1.18 namespace conflicts and therefore does not protect CGI applications fr
    24Monitor
  • CVE-2010-4181Directory traversal vulnerability in Yaws 1.89 allows remote attackers to read arbitrary files via ..\ (dot dot backslash) and other sequenc
    23Monitor
  • CVE-2009-4495Yaws 1.85 writes data to a log file without sanitizing non-printable characters, which might allow remote attackers to modify a window's tit
    23Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:yaws1.91-2 · Debian:12Package registry (OSV)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Metasploit module ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Metasploit moduleauxiliary/scanner/http/yaws_traversalYaws Web Server Directory Traversalauxiliary2011-11-25

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Metasploit-2923 d
  2. Published
  3. TodaySep 30, 2026+2500 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

nvd-primary

Root cause

A user-supplied file name is joined with the allowed directory, but the result is never checked to confirm it is still inside that directory.

The bug in code

The whole CWE-22 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
const file = path.join(ROOT, req.query.name);res.sendFile(file);

Fixed

ts
const file = path.resolve(ROOT, req.query.name);if (!file.startsWith(ROOT + path.sep)) {  return res.sendStatus(400);}res.sendFile(file);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Noroxi analysis

No Noroxi analysis for this record yet

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Change log

  1. Fix✗ → ✓

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References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records