#VU15967 Out-of-bounds write in LibTIFF - CVE-2018-18557

Vulnerability identifier: #VU15967

Vulnerability risk: High

CVSSv4.0: 8.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Amber]

CVE-ID: CVE-2018-18557

CWE-ID: CWE-787

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
LibTIFF
Universal components / Libraries / Libraries used by multiple products

Vendor: LibTIFF

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to decoding of arbitrarily-sized JBIG into a buffer, ignoring the buffer size. A remote unauthenticated attacker can supply specially crafted input, trigger a tif_jbig.c JBIGDecode out-of-bounds write and execute arbitrary code with elevated privileges.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

LibTIFF: 4.0.9

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External links
https://gitlab.com/libtiff/libtiff/merge_requests/38

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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. However, proof of concept for this vulnerability is available.