NULL pointer dereference in GNU Tar

1) NULL pointer dereference

EUVDB-ID: #VU18058

Risk: Low

CVSSv4.0: 4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2019-9923

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 dreference error in sparse.c in when parsing certain archives that have malformed extended headers. A remote attacker can perform a denial of service (DoS) attack.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Tar: 1.13 - 1.31

CPE2.3

• cpe:2.3:a:gnu:tar:1.13:*:*:*:*:*:*:*
• cpe:2.3:a:gnu:tar:1.13.5:*:*:*:*:*:*:*
• cpe:2.3:a:gnu:tar:1.13.11:*:*:*:*:*:*:*

External links

https://git.savannah.gnu.org/cgit/tar.git/commit/?id=cb07844454d8cc9fb21f53ace75975f91185a120
https://savannah.gnu.org/bugs/?55369
https://bugs.launchpad.net/ubuntu/+source/tar/+bug/1810241

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.