Oracle Linux 7 : dhcp (ELSA-2021-2357)
high Nessus Plugin ID 150497
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Synopsis
The remote Oracle Linux host is missing a security update.Description
The remote Oracle Linux 7 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2021-2357 advisory.- In ISC DHCP 4.1-ESV-R1 -> 4.1-ESV-R16, ISC DHCP 4.4.0 -> 4.4.2 (Other branches of ISC DHCP (i.e., releases in the 4.0.x series or lower and releases in the 4.3.x series) are beyond their End-of-Life (EOL) and no longer supported by ISC. From inspection it is clear that the defect is also present in releases from those series, but they have not been officially tested for the vulnerability), The outcome of encountering the defect while reading a lease that will trigger it varies, according to: the component being affected (i.e., dhclient or dhcpd) whether the package was built as a 32-bit or 64-bit binary whether the compiler flag -fstack-protection-strong was used when compiling In dhclient, ISC has not successfully reproduced the error on a 64-bit system. However, on a 32-bit system it is possible to cause dhclient to crash when reading an improper lease, which could cause network connectivity problems for an affected system due to the absence of a running DHCP client process. In dhcpd, when run in DHCPv4 or DHCPv6 mode: if the dhcpd server binary was built for a 32-bit architecture AND the -fstack-protection-strong flag was specified to the compiler, dhcpd may exit while parsing a lease file containing an objectionable lease, resulting in lack of service to clients. Additionally, the offending lease and the lease immediately following it in the lease database may be improperly deleted. if the dhcpd server binary was built for a 64-bit architecture OR if the -fstack-protection-strong compiler flag was NOT specified, the crash will not occur, but it is possible for the offending lease and the lease which immediately followed it to be improperly deleted. (CVE-2021-25217)
Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.
Solution
Update the affected packages.See Also
Plugin Details
Severity: High
ID: 150497
File Name: oraclelinux_ELSA-2021-2357.nasl
Version: 1.2
Type: local
Agent: unix
Published: 6/10/2021
Updated: 6/10/2021
Dependencies: ssh_get_info.nasl
Risk Information
CVSS Score Source: CVE-2021-25217
VPR
Risk Factor: Medium
Score: 5.2
CVSS v2
Risk Factor: Low
Base Score: 3.3
Temporal Score: 2.4
Vector: AV:A/AC:L/Au:N/C:N/I:N/A:P
Temporal Vector: E:U/RL:OF/RC:C
CVSS v3
Risk Factor: High
Base Score: 7.4
Temporal Score: 6.4
Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Temporal Vector: E:U/RL:O/RC:C
Vulnerability Information
CPE: cpe:/o:oracle:linux:7, p-cpe:/a:oracle:linux:dhclient, p-cpe:/a:oracle:linux:dhcp, p-cpe:/a:oracle:linux:dhcp-common, p-cpe:/a:oracle:linux:dhcp-devel, p-cpe:/a:oracle:linux:dhcp-libs
Required KB Items: Host/OracleLinux, Host/RedHat/release, Host/RedHat/rpm-list, Host/local_checks_enabled
Exploit Ease: No known exploits are available
Patch Publication Date: 6/10/2021
Vulnerability Publication Date: 5/26/2021
Reference Information
CVE: CVE-2021-25217
IAVB: 2021-B-0032