#VU49846 Heap-based buffer overflow in Dnsmasq - CVE-2020-25687

Vulnerability identifier: #VU49846

Vulnerability risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-25687

CWE-ID: CWE-122

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Dnsmasq
Server applications / DNS servers

Vendor: GNU

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error in rfc1035.c:extract_name(). A remote attacker can pass specially crafted data to the application, trigger heap-based buffer overflow and cause a denial of service condition on the target system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Dnsmasq: before 2.83

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External links
https://ics-cert.us-cert.gov/advisories/icsa-21-019-01
https://www.jsof-tech.com/disclosures/dnspooq/

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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.