Ubuntu update for Apache HTTP Server

Published: 2019-04-04 | Updated: 2019-04-08

Risk	Medium
Patch available	YES
Number of vulnerabilities	6
CVE-ID	CVE-2019-0211 CVE-2018-17189 CVE-2018-17199 CVE-2019-0196 CVE-2019-0217 CVE-2019-0220
CWE-ID	CWE-264 CWE-20 CWE-284 CWE-416 CWE-362
Exploitation vector	Network
Public exploit	Vulnerability #1 is being exploited in the wild.
Vulnerable software	apache2 (Ubuntu package) Operating systems & Components / Operating system package or component
Vendor	Canonical Ltd.

Security Bulletin

This security bulletin contains information about 6 vulnerabilities.

1) Privilege escalation

EUVDB-ID: #VU18110

Risk: Low

CVSSv4.0: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:A/U:Clear]

CVE-ID: CVE-2019-0211

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

Exploit availability: Yes

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists within MPM implementation due to the application does not properly maintain each child's listener bucket number in the scoreboard that may lead to unprivileged code or scripts run by server (e.g. via mod_php) to modify the scoreboard and abuse the privileged main process.

A local user can execute arbitrary code on the system with privileges of the Apache HTTP Server code process.

Mitigation

Update the affected packages.

Ubuntu 18.10: apache2-bin - 2.4.34-1ubuntu2.1
Ubuntu 18.04 LTS: apache2-bin - 2.4.29-1ubuntu4.6
Ubuntu 16.04 LTS: apache2-bin - 2.4.18-2ubuntu3.10
Ubuntu 14.04 LTS: apache2-bin - 2.4.7-1ubuntu4.22

Vulnerable software versions

apache2 (Ubuntu package): 2.4.7-1ubuntu4.1 - 2.4.29-1ubuntu4.5

CPE2.3

External links

https://usn.ubuntu.com/3937-1/

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.

2) Input validation error

EUVDB-ID: #VU17177

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-2018-17189

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The weakness exists due to an error when handling malicious input. A remote attacker can send a specially crafted request bodies in a slow loris way to plain resources and cause the h2 stream for that request unnecessarily occupied a server thread cleaning up that incoming data.

Mitigation

Update the affected packages.

Ubuntu 18.10: apache2-bin - 2.4.34-1ubuntu2.1
Ubuntu 18.04 LTS: apache2-bin - 2.4.29-1ubuntu4.6
Ubuntu 16.04 LTS: apache2-bin - 2.4.18-2ubuntu3.10
Ubuntu 14.04 LTS: apache2-bin - 2.4.7-1ubuntu4.22

Vulnerable software versions

apache2 (Ubuntu package): 2.4.7-1ubuntu4.1 - 2.4.29-1ubuntu4.5

CPE2.3

External links

https://usn.ubuntu.com/3937-1/

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) Security restrictions bypass

EUVDB-ID: #VU17178

Risk: Low

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:Clear]

CVE-ID: CVE-2018-17199

CWE-ID: CWE-284 - Improper Access Control

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass security restrictions on the target system.

The weakness exists due to mod_session checks the session expiry time before decoding the session. A remote attacker сan cause session expiry time to be ignored for mod_session_cookie sessions since the expiry time is loaded when the session is decoded and reuse old session credentials or session IDs, which the attacker could use to access web pages previously accessed by a targeted user.

Mitigation

Update the affected packages.

Ubuntu 18.10: apache2-bin - 2.4.34-1ubuntu2.1
Ubuntu 18.04 LTS: apache2-bin - 2.4.29-1ubuntu4.6
Ubuntu 16.04 LTS: apache2-bin - 2.4.18-2ubuntu3.10
Ubuntu 14.04 LTS: apache2-bin - 2.4.7-1ubuntu4.22

Vulnerable software versions

apache2 (Ubuntu package): 2.4.7-1ubuntu4.1 - 2.4.29-1ubuntu4.5

CPE2.3

External links

https://usn.ubuntu.com/3937-1/

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) Use-after-free

EUVDB-ID: #VU18109

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-2019-0196

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

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

The vulnerability exists due to a use-after-free error within the mod_http2 module when processing HTTP/2 requests. A remote attacker can make the application to access freed memory during string comparison when determining the method of a request and process the request incorrectly.

Successful exploitation of the vulnerability may allow an attacker to gain access to sensitive information or perform a denial of service attack.

Mitigation

Update the affected packages.

Ubuntu 18.10: apache2-bin - 2.4.34-1ubuntu2.1
Ubuntu 18.04 LTS: apache2-bin - 2.4.29-1ubuntu4.6
Ubuntu 16.04 LTS: apache2-bin - 2.4.18-2ubuntu3.10
Ubuntu 14.04 LTS: apache2-bin - 2.4.7-1ubuntu4.22

Vulnerable software versions

apache2 (Ubuntu package): 2.4.7-1ubuntu4.1 - 2.4.29-1ubuntu4.5

CPE2.3

External links

https://usn.ubuntu.com/3937-1/

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) Race condition

EUVDB-ID: #VU18111

Risk: Low

CVSSv4.0: 1.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear]

CVE-ID: CVE-2019-0217

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

The vulnerability allows a remote authenticated user to impersonate other users.

The vulnerability exists due to a race condition within the mod_auth_digests module. A remote authenticated attacker can send a series of requests and impersonate other users under a threaded MPM.

Mitigation

Update the affected packages.

Ubuntu 18.10: apache2-bin - 2.4.34-1ubuntu2.1
Ubuntu 18.04 LTS: apache2-bin - 2.4.29-1ubuntu4.6
Ubuntu 16.04 LTS: apache2-bin - 2.4.18-2ubuntu3.10
Ubuntu 14.04 LTS: apache2-bin - 2.4.7-1ubuntu4.22

Vulnerable software versions

apache2 (Ubuntu package): 2.4.7-1ubuntu4.1 - 2.4.29-1ubuntu4.5

CPE2.3

External links

https://usn.ubuntu.com/3937-1/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user 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: #VU18113

Risk: Low

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

CVE-ID: CVE-2019-0220

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The vulnerability exists due to the web server does not merge consecutive slashes in URLs, that can lead to incorrect processing of requests when accessing CGI programs. Such web server behavior may lead to security restrictions bypass.

Mitigation

Update the affected packages.

Ubuntu 18.10: apache2-bin - 2.4.34-1ubuntu2.1
Ubuntu 18.04 LTS: apache2-bin - 2.4.29-1ubuntu4.6
Ubuntu 16.04 LTS: apache2-bin - 2.4.18-2ubuntu3.10
Ubuntu 14.04 LTS: apache2-bin - 2.4.7-1ubuntu4.22

Vulnerable software versions

apache2 (Ubuntu package): 2.4.7-1ubuntu4.1 - 2.4.29-1ubuntu4.5

CPE2.3

External links

https://usn.ubuntu.com/3937-1/

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.