CVE-2016-1000111Network attack vector

Outbound traffic redirection via Proxy header injection

Published Mar 11, 2020 · Updated Aug 6, 2024

HTTPoxy in Twisted before 16.3.1 allows remote attackers to redirect CGI application outbound HTTP traffic through an arbitrary proxy. twisted.web.twcgi.CGIScript exposes the untrusted Proxy request header as HTTP_PROXY without resolving the RFC 3875 namespace collision. Exploitation requires a CGI application that trusts HTTP_PROXY for outbound requests, enabling traffic redirection without direct host compromise.

CVSS severity5.3
Medium
EPSS probability2.76%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTTPoxy in Twisted before 16.3.1 allows remote attackers to redirect CGI application outbound HTTP traffic through an arbitrary proxy. twisted.web.twcgi.CGIScript exposes the untrusted Proxy request header as HTTP_PROXY without resolving the RFC 3875 namespace collision. Exploitation requires a CGI application that trusts HTTP_PROXY for outbound requests, enabling traffic redirection without direct host compromise.

The record

CVE
CVE-2016-1000111
Published
Mar 11, 2020
Updated
Aug 6, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-425, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 11, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 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

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:P/A:N
6.9GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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-425Direct Request ('Forced Browsing')
T1557Adversary-in-the-Middle

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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