Improper input validation in ISC DHCP

1) Input validation error

EUVDB-ID: #VU53609

Risk: Medium

CVSSv4.0: 1.3 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-25217

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack or gain access to sensitive information.

The vulnerability exists due to insufficient validation of options data stored in DHCP leases. A remote attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack or gain access to sensitive information.

Both dhcpd and dhclient are affected by the vulnerability.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

DHCP: 3.0 - 4.4.2

CPE2.3

• cpe:2.3:a:isc:dhcp:3.0.6:*:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:3.1.3:*:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:4.1-esv:*:*:*:*:*:*:*
• cpe:2.3:a:isc:dhcp:4.4.2:*:*:*:*:*:*:*

External links

https://kb.isc.org/docs/cve-2021-25217

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.