CVE-2020-1695Network attack vector

Response header injection via accepted newline

Published May 19, 2020 · Updated Aug 4, 2024

Improper input validation in RESTEasy 3.x before 3.12.0.Final and 4.x before 4.6.0.Final allows remote attackers to inject response headers. MediaTypeHeaderDelegate.isValid accepts a newline in an untrusted media-type string, allowing the resulting illegal header to enter the server response. Exploitation requires an application path that passes attacker-controlled media-type input into the delegate; successful injection can alter the constructed response.

CVSS severity7.5
High
EPSS probability1.97%
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 RESTEasy 3.x before 3.12.0.Final and 4.x before 4.6.0.Final allows remote attackers to inject response headers. MediaTypeHeaderDelegate.isValid accepts a newline in an untrusted media-type string, allowing the resulting illegal header to enter the server response. Exploitation requires an application path that passes attacker-controlled media-type input into the delegate; successful injection can alter the constructed response.

The record

CVE
CVE-2020-1695
Published
May 19, 2020
Updated
Aug 4, 2024
Vendor
Red Hat
Product
RESTEasy
Classifications
CWE-20, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 19, 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

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Is a vulnerable build present?

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

  1. Affected versionversion=all resteasy 3.x.x versions prior to 3.12.0.Final
  2. Affected versionversion=all resteasy 4.x.x versions prior to 4.6.0.Final

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Red Hat · RESTEasyversion=all resteasy 3.x.x versions prior to 3.12.0.Final; version=all resteasy 4.x.x versions prior to 4.6.0.Final

Published CVSS scores

7.5Red HatCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
7.5CVE.orgCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
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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