#VU50921 NULL pointer dereference in libxls - CVE-2020-27819

Vulnerability identifier: #VU50921

Vulnerability risk: Medium

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:Green]

CVE-ID: CVE-2020-27819

CWE-ID: CWE-476

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
libxls
Client/Desktop applications / Multimedia software

Vendor: libxls.sourceforge.net

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 within the libxls/xls2csv.c file in libxls when parsing XLS cells. A remote attacker can trigger denial of service conditions via crafted XLS file.

Mitigation
Install update from vendor's website.

Vulnerable software versions

libxls: 0.2.0 - 1.6.2 rc0

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1903296
https://github.com/libxls/libxls/issues/84

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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.