CVE-2015-3154Network attack vector

HTTP response splitting via unfiltered mail headers

Published Jan 27, 2020 · Updated Aug 6, 2024

CRLF injection in Zend Framework before 1.12.12, 2.x before 2.3.8, and 2.4.x before 2.4.1 allows remote attackers to split HTTP responses. Zend\Mail header handling accepts carriage-return and line-feed sequences in untrusted field values, allowing extra headers or a header-body separator to be emitted. Exploitation requires a consuming application to place attacker-controlled email header content into an HTTP response; injected fields can alter that response.

CVSS severity6.1
Medium
EPSS probability1.01%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CRLF injection in Zend Framework before 1.12.12, 2.x before 2.3.8, and 2.4.x before 2.4.1 allows remote attackers to split HTTP responses. Zend\Mail header handling accepts carriage-return and line-feed sequences in untrusted field values, allowing extra headers or a header-body separator to be emitted. Exploitation requires a consuming application to place attacker-controlled email header content into an HTTP response; injected fields can alter that response.

The record

CVE
CVE-2015-3154
Published
Jan 27, 2020
Updated
Aug 6, 2024
Vendor
Zend
Product
Zend Framework
Classifications
CWE-74, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 27, 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?

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

  1. Affected versionversion=2.4.x before 2.4.1
  2. Affected versionversion=2.x before 2.3.8
  3. Affected versionversion=before 1.12.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zend · Zend Frameworkversion=2.4.x before 2.4.1; version=2.x before 2.3.8; version=before 1.12.12

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/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-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
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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