Denial of service in libarchive

Published: 2019-09-02 | Updated: 2019-09-04

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2019-1000020 CVE-2019-1000019
CWE-ID	CWE-400 CWE-125
Exploitation vector	Network
Public exploit	Public exploit code for vulnerability #1 is available.
Vulnerable software Subscribe	libarchive Client/Desktop applications / Software for archiving
Vendor	libarchive

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

Updated: 04.09.2019

Added vulnerability #2, fixed errors in version numbering for vulnerability #1.

1) Resource exhaustion

EUVDB-ID: #VU20541

Risk: Medium

CVSSv3.1: 5.9 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2019-1000020

CWE-ID: CWE-400 - Resource exhaustion

Exploit availability: No

Description

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

The vulnerability exists due to improper parsing of ISO9660 files. A remote attacker can persuade a user to access an ISO9660, trigger an infinite loop condition and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

libarchive: 2.8.0 - 3.2.0

External links

http://github.com/libarchive/libarchive/pull/1120
http://github.com/libarchive/libarchive/pull/1120/commits/8312eaa576014cd9b965012af51bc1f967b12423

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 trick the victim to open a a specially crafted archive.

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.

2) Out-of-bounds read

EUVDB-ID: #VU20838

Risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-1000019

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

Exploit availability: No

Description

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

The vulnerability exists due to a boundary condition in the header_bytes() function in archive_read_support_format_7zip.c when decompressing 7zip archives. A remote attacker can create a specially crafted 7zip file, trick the victim into opening it, trigger out-of-bounds read error and crash the affected application.

Mitigation

Install update from vendor's website.