Multiple vulnerabilities in Apache HTTP Server

1) Out-of-bounds write

EUVDB-ID: #VU20373

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-10081

CWE-ID: CWE-787 - Out-of-bounds write

Exploit availability: No

Description

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

The vulnerability exists due to a boundary error when processing HTTP/2 requests within the mod_http2 module, configured with "H2PushResource". A remote attacker can send specially crafted HTTP/2 requests to the affected server and perform denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Apache HTTP Server: 2.4.20 - 2.4.39

External links

http://httpd.apache.org/security/vulnerabilities_24.html

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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

2) Input validation error

EUVDB-ID: #VU20374

Risk: Medium

CVSSv3.1: 4.9 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2019-10098

CWE-ID: CWE-20 - Improper input validation

Exploit availability: Yes

Description

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

The vulnerability exists due to incorrect handling of encoded line break characters  within rewrite rules. A remote attacker can send a specially crafted HTTP request and potentially bypass security restrictions.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Apache HTTP Server: 2.4.0 - 2.4.39

External links

http://httpd.apache.org/security/vulnerabilities_24.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.

3) Cross-site scripting

EUVDB-ID: #VU20384

Risk: Low

CVSSv3.1: 4.1 [CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-10092

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Exploit availability: No

Description

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data on the mod_proxy error page. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Apache HTTP Server: 2.4.0 - 2.4.39

External links

http://httpd.apache.org/security/vulnerabilities_24.html

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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

4) NULL pointer dereference

EUVDB-ID: #VU20385

Risk: Low

CVSSv3.1: 2.4 [CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-10097

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 when processing PROXY header within the mod_remoteip. A remote attacker that controls a trusted proxy server can send a specially crafted PROXY header,  trigger stack overflow and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Apache HTTP Server: 2.4.33 - 2.4.38

External links

http://httpd.apache.org/security/vulnerabilities_24.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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

5) Use-after-free

EUVDB-ID: #VU20386

Risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-10082

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

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

The vulnerability exists due to a use-after-free error within the mod_http2 when handling connection shutdown. A remote attacker can send specially crafted requests to the affected server and make the mod_http2 to read memory that was already freed.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Apache HTTP Server: 2.4.18 - 2.4.39

External links

http://httpd.apache.org/security/vulnerabilities_24.html

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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

6) Resource management error

EUVDB-ID: #VU20340

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-9517

CWE-ID: CWE-399 - Resource Management Errors

Exploit availability: No

Description

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

The vulnerability exists due to incorrect implementation of HTTP/2 protocol. A remote attacker can  open the HTTP/2 window so the peer can send without constraint; however, they leave the TCP window closed so the peer cannot actually write (many of) the bytes on the wire. The attacker then sends a stream of requests for a large response object. Depending on how the servers queue the responses, this can consume excess memory, CPU, or both.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Apache HTTP Server: 2.4.20 - 2.4.39

External links

http://httpd.apache.org/security/vulnerabilities_24.html

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

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