CVE-2021-44224: Possible NULL dereference or SSRF in forward proxy configurations in Apache HTTP Server 2.4.51 and earlier

Published Dec 20, 2021
·
Updated

A crafted URI sent to httpd configured as a forward proxy (ProxyRequests on) can cause a crash (NULL pointer dereference) or, for configurations mixing forward and reverse proxy declarations, can allow for requests to be directed to a declared Unix Domain Socket endpoint (Server Side Request Forgery). This issue affects Apache HTTP Server 2.4.7 up to 2.4.51 (included).

Other sources

AMD. A buffer overflow issue was addressed with improved memory handling.

— Apple

AMD. A memory corruption issue was addressed with improved state management.

— Apple

apache. Multiple issues were addressed by updating apache to version 2.4.53.

— Apple

There's a null pointer dereference and server-side request forgery flaw in httpd's modproxy module, when it is configured to be used as a forward proxy. A crafted packet could be sent on the adjacent network to the forward proxy that could cause a crash, or potentially SSRF via misdirected Unix Domain Socket requests. In the worst case, this could cause a denial of service or compromise to confidentiality of data.

Credit

CVE-2021-44224, CVE-2021-44790, CVE-2022-22719, CVE-2022-22720, CVE-2022-22721, Lockheed Martin Red Team, an anonymous researcher, Jeremy Brown(Trend Micro Zero Day Initiative), Michael DePlante@@izobashi(Trend Micro Zero Day Initiative), Qi Sun(Trend Micro), Ye Zhang@@co0py_Cat(Baidu Security), Robert Ai(Trend Micro), Arsenii Kostromin (0x3c3e), Yonghwi Jin@@jinmo123(Theori), Linus Henze(Pinauten GmbH), Liu Long(Ant Security Light), Jack Dates(RET2 Systems Inc), Antonio Zekic@@antoniozekic, Jeonghoon Shin(Theori working with Trend Micro Zero Day Initiative), Peter Nguyễn Vũ Hoàng@@peternguyen14(STAR Labs), Ned Williamson(Google Project Zero), @@gorelics(BreakPoint), (BreakPoint), Ron Masas(BreakPoint), Wojciech Reguła@@_r3ggi(SecuRing), Arsenii Kostromin (0x3c3e)(Microsoft), Jonathan Bar Or(Microsoft), Zhipeng Huo@@R3dF09(Tencent Security Xuanwu Lab), Yuebin Sun@@yuebinsun2020(Tencent Security Xuanwu Lab), Max Shavrick@@_mxms(the Google Security Team), Zubair Ashraf(Crowdstrike), CVE-2022-0778, CVE-2022-23308, Mickey Jin@@patch1t, @@gorelics, Peter Nguyễn Vũ Hoàng(STAR Labs), Felix Poulin-Belanger, Antonio Cheong Yu Xuan(YCISCQ), CVE-2021-4136, CVE-2021-4166, CVE-2021-4173, CVE-2021-4187, CVE-2021-4192, CVE-2021-4193, CVE-2021-46059, CVE-2022-0128, Heige(KnownSec 404 Team), Bo Qu(Palo Alto Networks), Scarlet Raine, Wang Yu(Cyberserval), CVE-2022-0530, Tavis Ormandy, CVE-2021-45444, ABC Research s.r.o, Jon Thompson(Evolve), IA), actae0n(Blacksun Hackers Club working with Trend Micro Zero Day Initiative), Andrew Williams(Google), Avi Drissman(Google), chenyuwang@@mzzzz__(Tencent Security Xuanwu Lab), Jordy Zomer@@pwningsystems, Paul Walker(Bury), Nathaniel Ekoniak(Ennate Technologies), Gergely Kalman@@gergely_kalman(Mandiant), (Mandiant), Joshua Mason(Mandiant), Ron Waisberg(SecuRing), an anonymous researcher(SecuRing), (Perception Point), Ron Hass@@ronhass7(Perception Point), ryuzaki, Chijin Zhou(ShuiMuYuLin Ltd), Tsinghua wingtecher lab, Jeonghoon Shin(Theori), SorryMybad@@S0rryMybad(Kunlun Lab), Dongzhuo Zhao(ADLab of Venustech)

Affected Software

45 affected componentsFixes available
redhat/jbcs-httpd24-httpd<0:2.4.51-28.el8
0:2.4.51-28.el8
redhat/jbcs-httpd24-httpd<0:2.4.51-28.el7
0:2.4.51-28.el7
redhat/httpd24-httpd<0:2.4.34-23.el7.5
0:2.4.34-23.el7.5
debian/apache2
2.4.38-3+deb10u82.4.38-3+deb10u102.4.56-1~deb11u22.4.56-1~deb11u12.4.57-22.4.57-32.4.58-1
Apple macOS Big Sur<11.6.6
11.6.6
Apple Catalina
Apple macOS Monterey<12.4
12.4
Apache HTTP Server>=2.4.7<2.4.52
Fedoraproject Fedora=34
Fedoraproject Fedora=35
Fedoraproject Fedora=36
Debian Debian Linux=10.0
Debian Debian Linux=11.0
Tenable Tenable.Sc>=5.14.0<5.20.0
Tenable Tenable.Sc>=5.16.0<202201.1
Oracle Communications Element Manager<9.0
Oracle Communications Operations Monitor=4.0
Oracle Communications Operations Monitor=4.3
Oracle Communications Operations Monitor=4.4
Oracle Communications Operations Monitor=5.0
Oracle Communications Session Report Manager<9.0
Oracle Communications Session Route Manager<9.0
Oracle HTTP Server
Oracle HTTP Server=12.2.1.3.0
Oracle HTTP Server=12.2.1.4.0
Oracle Instantis Enterprisetrack=17.1
Oracle Instantis Enterprisetrack=17.2
Oracle Instantis Enterprisetrack=17.3
Apple iOS and macOS=10.15.7
Apple iOS and macOS=10.15.7-security_update_2020-001
Apple iOS and macOS=10.15.7-security_update_2021-001
Apple iOS and macOS=10.15.7-security_update_2021-002
Apple iOS and macOS=10.15.7-security_update_2021-003
Apple iOS and macOS=10.15.7-security_update_2021-004
Apple iOS and macOS=10.15.7-security_update_2021-005
Apple iOS and macOS=10.15.7-security_update_2021-006
Apple iOS and macOS=10.15.7-security_update_2021-007
Apple iOS and macOS=10.15.7-security_update_2021-008
Apple iOS and macOS=10.15.7-security_update_2022-001
Apple iOS and macOS=10.15.7-security_update_2022-002
Apple iOS and macOS=10.15.7-security_update_2022-003
Apple macOS<10.15.7
Apple macOS>=11.0<11.6.6
Apple macOS>=12.0.0<12.4
redhat/httpd<2.4.52
2.4.52

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade redhat/jbcs-httpd24-httpd to a version that resolves this vulnerability.

    Fixed in 0:2.4.51-28.el8
  2. Upgrade

    Upgrade redhat/jbcs-httpd24-httpd to a version that resolves this vulnerability.

    Fixed in 0:2.4.51-28.el7
  3. Upgrade

    Upgrade redhat/httpd24-httpd to a version that resolves this vulnerability.

    Fixed in 0:2.4.34-23.el7.5
  4. Upgrade

    Upgrade debian/apache2 to a version that resolves this vulnerability.

    Fixed in 2.4.38-3+deb10u8Fixed in 2.4.38-3+deb10u10Fixed in 2.4.56-1~deb11u2Fixed in 2.4.56-1~deb11u1Fixed in 2.4.57-2Fixed in 2.4.57-3Fixed in 2.4.58-1
  5. Upgrade

    Upgrade Apple macOS to a version that resolves this vulnerability.

    Fixed in 11.6.6
  6. Upgrade

    Upgrade macOS to a version that resolves this vulnerability.

    Fixed in 12.4
  7. Upgrade

    Upgrade redhat/httpd to a version that resolves this vulnerability.

    Fixed in 2.4.52
  8. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 12.4
  9. Upgrade

    Upgrade apache to a version that resolves this vulnerability.

    Fixed in 2.4.53

Event History

Dec 20, 2021
CVE Published
12:00 AM
CVE Published
via MITRE·11:20 AM
Data Sourced
via MITRE·11:20 AM
DescriptionWeakness
Dec 21, 2021
Data Sourced
via Red Hat·04:49 PM
DescriptionSeverityAffected Software
May 16, 2022
Data Sourced
via Apple·12:00 AM
DescriptionWeaknessAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

What is CVE-2021-44224?

CVE-2021-44224 is a vulnerability in the Apache HTTP server that allows for a null pointer dereference and server-side request forgery (SSRF) when the mod_proxy module is configured as a forward proxy.

2

How does CVE-2021-44224 impact the Apache HTTP server?

CVE-2021-44224 can cause a crash or allow for SSRF attacks if a crafted packet is sent to the forward proxy on the adjacent network.

3

What is the severity of CVE-2021-44224?

CVE-2021-44224 has a severity value of 7, indicating a high severity.

4

How can I fix CVE-2021-44224?

To fix CVE-2021-44224, update Apache HTTP server to version 2.4.53 or later.

5

Are there any references for CVE-2021-44224?

Yes, you can find references for CVE-2021-44224 at the following links: [Link 1](https://support.apple.com/en-us/HT213257), [Link 2](https://support.apple.com/en-us/HT213255), [Link 3](https://support.apple.com/en-us/HT213256).

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