CVE-2019-19886Public exploitNetwork attack vector

Service interruption via empty-name cookie parsing

Published Jan 21, 2020 · Updated Aug 5, 2024

Denial of service in Trustwave ModSecurity 3.0.0 through 3.0.3 allows remote attackers to crash Nginx workers via a crafted Cookie header. Transaction::addRequestHeader passes the Cookie value to a parser that mishandles an empty cookie name such as =foo and throws an uncaught out-of-range exception. No authentication or user interaction is required; repeated requests continually terminate respawned workers and leave the protected server unresponsive.

CVSS severity7.5
High
EPSS probability2.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Trustwave ModSecurity 3.0.0 through 3.0.3 allows remote attackers to crash Nginx workers via a crafted Cookie header. Transaction::addRequestHeader passes the Cookie value to a parser that mishandles an empty cookie name such as =foo and throws an uncaught out-of-range exception. No authentication or user interaction is required; repeated requests continually terminate respawned workers and leave the protected server unresponsive.

The record

CVE
CVE-2019-19886
Published
Jan 21, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-404, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 21, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

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.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-404Improper Resource Shutdown or Release
T1499.004Application or System Exploitation

Public exploit references

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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