CVE-2020-10705Network attack vector

Unauthenticated denial of service via Expect header

Published Jun 10, 2020 · Updated Aug 4, 2024

Resource exhaustion in Red Hat Undertow before 2.1.1.Final allows remote attackers to interrupt service via crafted HTTP requests. In HttpReadListener, processing certain requests carrying the Expect: 100-continue header consumes memory without an effective limit until allocation fails. No authentication or user interaction is required; the bounded impact is an out-of-memory failure and resulting service interruption.

CVSS severity7.5
High
EPSS probability1.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Red Hat Undertow before 2.1.1.Final allows remote attackers to interrupt service via crafted HTTP requests. In HttpReadListener, processing certain requests carrying the Expect: 100-continue header consumes memory without an effective limit until allocation fails. No authentication or user interaction is required; the bounded impact is an out-of-memory failure and resulting service interruption.

The record

CVE
CVE-2020-10705
Published
Jun 10, 2020
Updated
Aug 4, 2024
Vendor
Red Hat
Product
Undertow
Classifications
CWE-770, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 10, 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=Versions before Undertow 2.1.1.Final.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Red Hat · Undertowversion=Versions before Undertow 2.1.1.Final.

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499.004Application or System Exploitation

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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