Detections
Analytics
Oracle Linux 7 : Unbreakable Enterprise kernel-container (ELSA-2021-9058)
high Nessus Plugin ID 146549
Language:
Synopsis
The remote Oracle Linux host is missing one or more security updates.Description
The remote Oracle Linux 7 host has a package installed that is affected by multiple vulnerabilities as referenced in the ELSA-2021-9058 advisory.- An issue was discovered in the Linux kernel 3.11 through 5.10.16, as used by Xen. To service requests to the PV backend, the driver maps grant references provided by the frontend. In this process, errors may be encountered. In one case, an error encountered earlier might be discarded by later processing, resulting in the caller assuming successful mapping, and hence subsequent operations trying to access space that wasn't mapped. In another case, internal state would be insufficiently updated, preventing safe recovery from the error. This affects drivers/block/xen-blkback/blkback.c. (CVE-2021-26930)
- An issue was discovered in the Linux kernel 2.6.39 through 5.10.16, as used in Xen. Block, net, and SCSI backends consider certain errors a plain bug, deliberately causing a kernel crash. For errors potentially being at least under the influence of guests (such as out of memory conditions), it isn't correct to assume a plain bug. Memory allocations potentially causing such crashes occur only when Linux is running in PV mode, though. This affects drivers/block/xen-blkback/blkback.c and drivers/xen/xen-scsiback.c.
(CVE-2021-26931)
- An issue was discovered in the Linux kernel 3.2 through 5.10.16, as used by Xen. Grant mapping operations often occur in batch hypercalls, where a number of operations are done in a single hypercall, the success or failure of each one is reported to the backend driver, and the backend driver then loops over the results, performing follow-up actions based on the success or failure of each operation. Unfortunately, when running in PV mode, the Linux backend drivers mishandle this: Some errors are ignored, effectively implying their success from the success of related batch elements. In other cases, errors resulting from one batch element lead to further batch elements not being inspected, and hence successful ones to not be possible to properly unmap upon error recovery. Only systems with Linux backends running in PV mode are vulnerable. Linux backends run in HVM / PVH modes are not vulnerable. This affects arch/*/xen/p2m.c and drivers/xen/gntdev.c. (CVE-2021-26932)
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
Solution
Update the affected kernel-uek-container package.See Also
Plugin Details
Severity: High
ID: 146549
File Name: oraclelinux_ELSA-2021-9058.nasl
Version: 1.6
Type: local
Agent: unix
Published: 2/16/2021
Updated: 1/16/2024
Supported Sensors: Continuous Assessment, Frictionless Assessment Agent, Nessus Agent, Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 5.9
CVSS v2
Risk Factor: Medium
Base Score: 4.6
Temporal Score: 3.4
Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:P
CVSS Score Source: CVE-2021-26930
CVSS v3
Risk Factor: High
Base Score: 7.8
Temporal Score: 6.8
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
Vulnerability Information
CPE: p-cpe:/a:oracle:linux:kernel-uek-container, cpe:/o:oracle:linux:7
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: 2/17/2021
Vulnerability Publication Date: 2/16/2021