Fedora 35 update for httpd

Published: 2021-09-17

Risk	High
Patch available	YES
Number of vulnerabilities	10
CVE-ID	CVE-2020-35452 CVE-2021-26690 CVE-2021-26691 CVE-2020-13950 CVE-2019-17567 CVE-2021-30641 CVE-2021-40438 CVE-2021-39275 CVE-2021-36160 CVE-2021-34798
CWE-ID	CWE-121 CWE-476 CWE-264 CWE-20 CWE-918 CWE-119 CWE-125
Exploitation vector	Network
Public exploit	Vulnerability #7 is being exploited in the wild.
Vulnerable software	Fedora Operating systems & Components / Operating system httpd Operating systems & Components / Operating system package or component
Vendor	Fedoraproject

Security Bulletin

This security bulletin contains information about 10 vulnerabilities.

1) Stack-based buffer overflow

EUVDB-ID: #VU53775

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-35452

CWE-ID: CWE-121 - Stack-based buffer overflow

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error when processing Digest nounces in mod_auth_digest. A remote unauthenticated attacker can send a specially crafted HTTP request, trigger stack overflow by one nul byte and crash the server.

Mitigation

Install updates from vendor's repository.

Vulnerable software versions

Fedora: 35

httpd: before 2.4.49-1.fc35

CPE2.3

External links

https://bodhi.fedoraproject.org/updates/FEDORA-2021-e3f6dd670d

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) NULL pointer dereference

EUVDB-ID: #VU53777

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-26690

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in mod_session. A remote attacker can pass specially crafted data to the application and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's repository.

Vulnerable software versions

Fedora: 35

httpd: before 2.4.49-1.fc35

CPE2.3

External links

https://bodhi.fedoraproject.org/updates/FEDORA-2021-e3f6dd670d

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

3) NULL pointer dereference

EUVDB-ID: #VU53776

Risk: Low

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-26691

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in mod_session. A a malicious backend server or SessionHeader can trigger a denial of service (DoS) condition.

Mitigation

Install updates from vendor's repository.

Vulnerable software versions

Fedora: 35

httpd: before 2.4.49-1.fc35

CPE2.3

External links

https://bodhi.fedoraproject.org/updates/FEDORA-2021-e3f6dd670d

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

4) NULL pointer dereference

EUVDB-ID: #VU53778

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-13950

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in mod_proxy_http. A remote attacker can pass specially crafted data to the application and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's repository.

Vulnerable software versions

Fedora: 35

httpd: before 2.4.49-1.fc35

CPE2.3

External links

https://bodhi.fedoraproject.org/updates/FEDORA-2021-e3f6dd670d

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

5) Security restrictions bypass

EUVDB-ID: #VU53780

Risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-17567

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to unspecified error within the mod_proxy_wstunnel and mod_proxy_http modules. If mod_proxy_wstunnel is configured on an URL that is not necessarily Upgraded by the origin server and is tunneling the whole connection regardless, thus allowing for subsequent requests on the same connection to pass through with no HTTP validation, authentication or authorization possibly configured.

Mitigation

Install updates from vendor's repository.

Vulnerable software versions

Fedora: 35

httpd: before 2.4.49-1.fc35

CPE2.3

External links

https://bodhi.fedoraproject.org/updates/FEDORA-2021-e3f6dd670d

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

6) Input validation error

EUVDB-ID: #VU53774

Risk: Medium

CVSSv4.0: 6.9 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-30641

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to incorrect parsing of Apache configuration files. An unexpected section could be matched with 'MergeSlashes OFF' option, leading to a potential security issue.

Mitigation

Install updates from vendor's repository.

Vulnerable software versions

Fedora: 35

httpd: before 2.4.49-1.fc35

CPE2.3

External links

https://bodhi.fedoraproject.org/updates/FEDORA-2021-e3f6dd670d

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

7) Server-Side Request Forgery (SSRF)

EUVDB-ID: #VU56678

Risk: High

CVSSv4.0: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:L/SI:N/SA:N/E:A/U:Amber]

CVE-ID: CVE-2021-40438

CWE-ID: CWE-918 - Server-Side Request Forgery (SSRF)

Exploit availability: Yes

Description

The disclosed vulnerability allows a remote attacker to perform SSRF attacks.

The vulnerability exists due to insufficient validation of user-supplied input within the mod_proxy module in Apache HTTP Server. A remote attacker can send a specially crafted HTTP request with a chosen uri-path and trick the web server to initiate requests to arbitrary systems.

Successful exploitation of this vulnerability may allow a remote attacker gain access to sensitive data, located in the local network or send malicious requests to other servers from the vulnerable system.

Mitigation

Install updates from vendor's repository.

Vulnerable software versions

Fedora: 35

httpd: before 2.4.49-1.fc35

CPE2.3

External links

https://bodhi.fedoraproject.org/updates/FEDORA-2021-e3f6dd670d

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.

8) Buffer overflow

EUVDB-ID: #VU56679

Risk: Medium

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-39275

CWE-ID: CWE-119 - Memory corruption

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system or perform a denial of service attack.

The vulnerability exists due to a boundary error within the ap_escape_quotes() function. A remote attacker can send a specially crafted request to the web server, trigger memory corruption and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system but requires that the Apache module passes untrusted data to the affected function.

According to vendor, No included modules pass untrusted data to these functions

Mitigation

Install updates from vendor's repository.

Vulnerable software versions

Fedora: 35

httpd: before 2.4.49-1.fc35

CPE2.3

External links

https://bodhi.fedoraproject.org/updates/FEDORA-2021-e3f6dd670d

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

9) Out-of-bounds read

EUVDB-ID: #VU56680

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-36160

CWE-ID: CWE-125 - Out-of-bounds read

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary condition in the mod_proxy_uwsgi module in Apache HTTP Server. A remote attacker can send an HTTP request with specially crafted uri-path, trigger an out-of-bounds read and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's repository.

Vulnerable software versions

Fedora: 35

httpd: before 2.4.49-1.fc35

CPE2.3

External links

https://bodhi.fedoraproject.org/updates/FEDORA-2021-e3f6dd670d

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

10) NULL pointer dereference

EUVDB-ID: #VU56681

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-34798

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error. A remote attacker can send a specially crafted HTTP request to the affected web server and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's repository.

Vulnerable software versions

Fedora: 35

httpd: before 2.4.49-1.fc35

CPE2.3

External links

https://bodhi.fedoraproject.org/updates/FEDORA-2021-e3f6dd670d

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.