CVE-2020-1757Network attack vector

Security bypass via semicolon path truncation

Published Apr 21, 2020 · Updated Aug 4, 2024

Improper input validation in Red Hat Undertow before 2.1.0.Final allows remote authenticated users to bypass URL security via crafted paths. The Servlet container truncates servletPath at a semicolon, causing application mapping to target a different path than the full request. Exploitation requires an application that relies on URL-based security mapping; successful requests can expose or alter resources according to the misrouted endpoint.

CVSS severity8.1
High
EPSS probability1.58%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Red Hat Undertow before 2.1.0.Final allows remote authenticated users to bypass URL security via crafted paths. The Servlet container truncates servletPath at a semicolon, causing application mapping to target a different path than the full request. Exploitation requires an application that relies on URL-based security mapping; successful requests can expose or alter resources according to the misrouted endpoint.

The record

CVE
CVE-2020-1757
Published
Apr 21, 2020
Updated
Aug 4, 2024
Vendor
Red Hat
Product
Undertow
Classifications
CWE-20, CWE-200, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 21, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=all undertow-1.x.x and undertow-2.x.x versions prior to undertow-2.1.0.Final
  2. Affected versionversion=all undertow-2.x.x SP1 versions prior to undertow-2.0.30.SP1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Red Hat · Undertowversion=all undertow-1.x.x and undertow-2.x.x versions prior to undertow-2.1.0.Final; version=all undertow-2.x.x SP1 versions prior to undertow-2.0.30.SP1

Published CVSS scores

8.1GitHub Advisory DatabaseCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
8.1NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
CWE-200Exposure of Sensitive Information
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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