Important: dhcp

Issue Overview:

A flaw was found in the Dynamic Host Configuration Protocol (DHCP). There is a discrepancy between the code that handles encapsulated option information in leases transmitted “on the wire” and the code which reads and parses lease information after it has been written to disk storage. This flaw allows an attacker to deliberately cause a situation where dhcpd while running in DHCPv4 or DHCPv6 mode, or the dhclient attempts to read a stored lease that contains option information, to trigger a stack-based buffer overflow in the option parsing code for colon-separated hex digits values. The highest threat from this vulnerability is to data confidentiality and integrity as well as service availability. (CVE-2021-25217)

Affected Packages:

dhcp

Note:

This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.

Issue Correction:
Run yum update dhcp to update your system.

New Packages:

aarch64:  
    dhcp-4.2.5-77.amzn2.1.3.aarch64  
    dhclient-4.2.5-77.amzn2.1.3.aarch64  
    dhcp-common-4.2.5-77.amzn2.1.3.aarch64  
    dhcp-libs-4.2.5-77.amzn2.1.3.aarch64  
    dhcp-devel-4.2.5-77.amzn2.1.3.aarch64  
    dhcp-debuginfo-4.2.5-77.amzn2.1.3.aarch64  
  
i686:  
    dhcp-4.2.5-77.amzn2.1.3.i686  
    dhclient-4.2.5-77.amzn2.1.3.i686  
    dhcp-common-4.2.5-77.amzn2.1.3.i686  
    dhcp-libs-4.2.5-77.amzn2.1.3.i686  
    dhcp-devel-4.2.5-77.amzn2.1.3.i686  
    dhcp-debuginfo-4.2.5-77.amzn2.1.3.i686  
  
src:  
    dhcp-4.2.5-77.amzn2.1.3.src  
  
x86_64:  
    dhcp-4.2.5-77.amzn2.1.3.x86_64  
    dhclient-4.2.5-77.amzn2.1.3.x86_64  
    dhcp-common-4.2.5-77.amzn2.1.3.x86_64  
    dhcp-libs-4.2.5-77.amzn2.1.3.x86_64  
    dhcp-devel-4.2.5-77.amzn2.1.3.x86_64  
    dhcp-debuginfo-4.2.5-77.amzn2.1.3.x86_64  

Additional References

Red Hat: CVE-2021-25217

Mitre: CVE-2021-25217