Red Hat Linux Enterprise 7 DHCP denial of service

Summaryinfo

A vulnerability identified as problematic has been detected in Red Hat Linux Enterprise 7. This issue affects some unknown processing of the component DHCP. The manipulation leads to denial of service. This vulnerability is uniquely identified as CVE-2019-6470. The attack is possible to be carried out remotely. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Red Hat Linux Enterprise 7 (Operating System) and classified as problematic. This issue affects some unknown functionality of the component DHCP. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. The summary by CVE is:

There had existed in one of the ISC BIND libraries a bug in a function that was used by dhcpd when operating in DHCPv6 mode. There was also a bug in dhcpd relating to the use of this function per its documentation, but the bug in the library function prevented this from causing any harm. All releases of dhcpd from ISC contain copies of this, and other, BIND libraries in combinations that have been tested prior to release and are known to not present issues like this. Some third-party packagers of ISC software have modified the dhcpd source, BIND source, or version matchup in ways that create the crash potential. Based on reports available to ISC, the crash probability is large and no analysis has been done on how, or even if, the probability can be manipulated by an attacker. Affects: Builds of dhcpd versions prior to version 4.4.1 when using BIND versions 9.11.2 or later, or BIND versions with specific bug fixes backported to them. ISC does not have access to comprehensive version lists for all repackagings of dhcpd that are vulnerable. In particular, builds from other vendors may also be affected. Operators are advised to consult their vendor documentation.

The weakness was disclosed 11/01/2019 (Website). The advisory is shared at access.redhat.com. The identification of this vulnerability is CVE-2019-6470 since 01/16/2019. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1499 for this issue. The advisory points out:

double-deletion of the released addresses in the dhcpv6 code leading to crash and possible DoS (CVE-2019-6470)

Upgrading to version 4.4.1 eliminates this vulnerability. The upgrade is hosted for download at access.redhat.com.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Operating System

Vendor

• Red Hat

Name

• Linux Enterprise

Version

• 7

License

• open-source

Website

• Vendor: https://www.redhat.com/

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion