CVE-2016-4975

mod_userdir CRLF injection

Severity Score

6.1

*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Possible CRLF injection allowing HTTP response splitting attacks for sites which use mod_userdir. This issue was mitigated by changes made in 2.4.25 and 2.2.32 which prohibit CR or LF injection into the "Location" or other outbound header key or value. Fixed in Apache HTTP Server 2.4.25 (Affected 2.4.1-2.4.23). Fixed in Apache HTTP Server 2.2.32 (Affected 2.2.0-2.2.31).

Posible inyección CRLF que permite ataques de separación de respuesta HTTP para los sitios que emplean mod_userdir. Este problema fue mitigado gracias a los cambios realizados en las versiones 2.4.25 y 2.2.32, que prohíben la inyección CR o LF en "Location" o en otro tipo de clave o valor de cabecera saliente. Esto se ha solucionado en Apache HTTP Server 2.4.25 (2.4.1-2.4.23 afectadas). Esto se ha solucionado en Apache HTTP Server 2.2.32 (2.2.0-2.2.31 afectadas).

It was found that Apache was vulnerable to a HTTP response splitting attack for sites which use mod_userdir. An attacker could use this flaw to inject CRLF characters into the HTTP header and could possibly gain access to secure data.

*Credits: The issue was discovered by Sergey Bobrov

CVSS Scores

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

None

Integrity

Partial

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2016-05-24 CVE Reserved
2018-08-14 CVE Published
2024-01-05 EPSS Updated
2024-09-16 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')
CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')

CAPEC

References (26)

URL	Tag	Source
http://www.securityfocus.com/bid/105093	Third Party Advisory
https://lists.apache.org/thread.html/56c2e7cc9deb1c12a843d0dc251ea7fd3e7e80293cde02fcd65286ba%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/84a3714f0878781f6ed84473d1a503d2cc382277e100450209231830%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/8d63cb8e9100f28a99429b4328e4e7cebce861d5772ac9863ba2ae6f%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/f7f95ac1cd9895db2714fa3ebaa0b94d0c6df360f742a40951384a53%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r04e89e873d54116a0635ef2f7061c15acc5ed27ef7500997beb65d6f%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r57608dc51b79102f3952ae06f54d5277b649c86d6533dcd6a7d201f7%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r75cbe9ea3e2114e4271bbeca7aff96117b50c1b6eb7c4772b0337c1f%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r9ea3538f229874c80a10af473856a81fbf5f694cd7f471cc679ba70b%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/r9f93cf6dde308d42a9c807784e8102600d0397f5f834890708bf6920%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/rb14daf9cc4e28d18cdc15d6a6ca74e565672fabf7ad89541071d008b%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/rc998b18880df98bafaade071346690c2bc1444adaa1a1ea464b93f0a%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/rcc44594d4d6579b90deccd4536b5d31f099ef563df39b094be286b9e%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/rd18c3c43602e66f9cdcf09f1de233804975b9572b0456cc582390b6f%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/rd336919f655b7ff309385e34a143e41c503e133da80414485b3abcc9%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/rdca61ae990660bacb682295f2a09d34612b7bb5f457577fe17f4d064%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/re1e3a24664d35bcd0a0e793e0b5fc6ca6c107f99a1b2c545c5d4b467%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/re3d27b6250aa8548b8845d314bb8a350b3df326cacbbfdfe4d455234%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/rf6449464fd8b7437704c55f88361b66f12d5b5f90bcce66af4be4ba9%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://lists.apache.org/thread.html/rfbaf647d52c1cb843e726a0933f156366a806cead84fbd430951591b%40%3Ccvs.httpd.apache.org%3E	Mailing List
https://security.netapp.com/advisory/ntap-20180926-0006	Third Party Advisory
https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03908en_us	X_refsource_confirm

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://httpd.apache.org/security/vulnerabilities_22.html#CVE-2016-4975	2023-11-07
https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2016-4975	2023-11-07
https://access.redhat.com/security/cve/CVE-2016-4975	2018-08-16
https://bugzilla.redhat.com/show_bug.cgi?id=1375968	2018-08-16

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.0 Search vendor "Apache" for product "Http Server" and version "2.2.0"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.2 Search vendor "Apache" for product "Http Server" and version "2.2.2"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.3 Search vendor "Apache" for product "Http Server" and version "2.2.3"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.4 Search vendor "Apache" for product "Http Server" and version "2.2.4"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.6 Search vendor "Apache" for product "Http Server" and version "2.2.6"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.8 Search vendor "Apache" for product "Http Server" and version "2.2.8"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.9 Search vendor "Apache" for product "Http Server" and version "2.2.9"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.10 Search vendor "Apache" for product "Http Server" and version "2.2.10"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.11 Search vendor "Apache" for product "Http Server" and version "2.2.11"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.12 Search vendor "Apache" for product "Http Server" and version "2.2.12"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.13 Search vendor "Apache" for product "Http Server" and version "2.2.13"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.14 Search vendor "Apache" for product "Http Server" and version "2.2.14"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.15 Search vendor "Apache" for product "Http Server" and version "2.2.15"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.16 Search vendor "Apache" for product "Http Server" and version "2.2.16"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.17 Search vendor "Apache" for product "Http Server" and version "2.2.17"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.18 Search vendor "Apache" for product "Http Server" and version "2.2.18"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.19 Search vendor "Apache" for product "Http Server" and version "2.2.19"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.20 Search vendor "Apache" for product "Http Server" and version "2.2.20"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.21 Search vendor "Apache" for product "Http Server" and version "2.2.21"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.22 Search vendor "Apache" for product "Http Server" and version "2.2.22"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.23 Search vendor "Apache" for product "Http Server" and version "2.2.23"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.24 Search vendor "Apache" for product "Http Server" and version "2.2.24"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.25 Search vendor "Apache" for product "Http Server" and version "2.2.25"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.26 Search vendor "Apache" for product "Http Server" and version "2.2.26"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.27 Search vendor "Apache" for product "Http Server" and version "2.2.27"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.29 Search vendor "Apache" for product "Http Server" and version "2.2.29"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.2.31 Search vendor "Apache" for product "Http Server" and version "2.2.31"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.1 Search vendor "Apache" for product "Http Server" and version "2.4.1"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.2 Search vendor "Apache" for product "Http Server" and version "2.4.2"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.3 Search vendor "Apache" for product "Http Server" and version "2.4.3"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.4 Search vendor "Apache" for product "Http Server" and version "2.4.4"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.6 Search vendor "Apache" for product "Http Server" and version "2.4.6"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.7 Search vendor "Apache" for product "Http Server" and version "2.4.7"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.9 Search vendor "Apache" for product "Http Server" and version "2.4.9"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.10 Search vendor "Apache" for product "Http Server" and version "2.4.10"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.12 Search vendor "Apache" for product "Http Server" and version "2.4.12"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.16 Search vendor "Apache" for product "Http Server" and version "2.4.16"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.17 Search vendor "Apache" for product "Http Server" and version "2.4.17"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.18 Search vendor "Apache" for product "Http Server" and version "2.4.18"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.20 Search vendor "Apache" for product "Http Server" and version "2.4.20"		-		Affected
Apache Search vendor "Apache"		Http Server Search vendor "Apache" for product "Http Server"				2.4.23 Search vendor "Apache" for product "Http Server" and version "2.4.23"		-		Affected