#VU16233 Stack-based buffer overflow in LibSass - CVE-2018-19838

Vulnerability identifier: #VU16233

Vulnerability risk: Low

CVSSv4.0: 5.5 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2018-19838

CWE-ID: CWE-121

Exploitation vector: Network

Exploit availability: No

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

Vendor: Sass

Description

The vulnerability allows a remote attacker to cause DoS condition.

The vulnerability exists due to stack-based buffer overflow in functions inside ast.cpp for IMPLEMENT_AST_OPERATORS expansion, as demonstrated by recursive calls involving clone(), cloneChildren(), and copy(). A remote attacker can send a specially crafted sass file, trigger memory corruption and cause the service to crash.

Mitigation
Update to version 3.5.5.

Vulnerable software versions

LibSass: 3.4.0 - 3.5.4

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External links
https://github.com/sass/libsass/issues/2660

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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.