#VU31883 Heap-based buffer overflow in re2c - CVE-2020-11958

Vulnerability identifier: #VU31883

Vulnerability risk: High

CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2020-11958

CWE-ID: CWE-122

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
re2c
Other software / Other software solutions

Vendor: www.re2c.org

Description

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

The vulnerability exists due to a boundary error within the Scanner::fill in parse/scanner.cc via a long lexeme. A remote attacker can create a specially crafted file, trick the victim into opening it, trigger heap-based buffer overflow and execute arbitrary code on the target system.

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

Mitigation
Install update from vendor's website.

Vulnerable software versions

re2c: 1.2 - 1.3

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External links
https://www.openwall.com/lists/oss-security/2020/04/21/1
https://blogs.gentoo.org/ago/2020/04/19/re2c-heap-overflow-in-scannerfill-scanner-cc/
https://github.com/skvadrik/re2c/commit/c4603ba5ce229db83a2a4fb93e6d4b4e3ec3776a
https://usn.ubuntu.com/4338-1/
https://usn.ubuntu.com/4338-2/
https://www.openwall.com/lists/oss-security/2020/04/19/1

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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.