Red Hat Enterprise Linux 8 update for the virt:rhel and virt-devel:rhel modules
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 2 |
| CVE-ID | CVE-2021-20257 CVE-2021-3930 |
| CWE-ID | CWE-835 CWE-193 |
| Exploitation vector | Network |
| Public exploit | N/A |
| Vulnerable software |
Red Hat CodeReady Linux Builder for IBM z Systems Operating systems & Components / Operating system Red Hat CodeReady Linux Builder for ARM 64 Operating systems & Components / Operating system Red Hat CodeReady Linux Builder for Power, little endian Operating systems & Components / Operating system Red Hat CodeReady Linux Builder for x86_64 Operating systems & Components / Operating system Red Hat Enterprise Linux for ARM 64 Operating systems & Components / Operating system Red Hat Enterprise Linux for Power, little endian Operating systems & Components / Operating system Red Hat Enterprise Linux for IBM z Systems Operating systems & Components / Operating system Red Hat Enterprise Linux for x86_64 Operating systems & Components / Operating system |
| Vendor | Red Hat Inc. |
Security Bulletin
This security bulletin contains information about 2 vulnerabilities.
1) Infinite loop
EUVDB-ID: #VU59085
Risk: Medium
CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]
CVE-ID: CVE-2021-20257
CWE-ID:
CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')
Exploit availability: No
DescriptionThe vulnerability allows a remote user to perform a denial of service (DoS) attack.
The vulnerability exists due to infinite loop in the e1000 NIC emulator when processing transmits (tx) descriptors in process_tx_desc of QEMU. A remote user can consume all available CPU resources and cause denial of service conditions.
MitigationInstall updates from vendor's website.
Red Hat CodeReady Linux Builder for IBM z Systems: 8.0
Red Hat CodeReady Linux Builder for ARM 64: 8.0
Red Hat CodeReady Linux Builder for Power, little endian: 8.0
Red Hat CodeReady Linux Builder for x86_64: 8.0
Red Hat Enterprise Linux for ARM 64: 8
Red Hat Enterprise Linux for Power, little endian: 8
Red Hat Enterprise Linux for IBM z Systems: 8
Red Hat Enterprise Linux for x86_64: 8.0
CPE2.3- cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_ibm_z_systems:8.0:*:*:*:*:*:*:*
- cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_arm_64:8.0:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_power_little_endian:8.0:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_x86_64:8.0:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64:8:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian:8:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems:8:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux:8.0:*:*:*:*:*:*:*
https://access.redhat.com/errata/RHSA-2021:5238
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
2) Off-by-one
EUVDB-ID: #VU58812
Risk: Medium
CVSSv4.0: 4.6 [CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]
CVE-ID: CVE-2021-3930
CWE-ID:
CWE-193 - Off-by-one Error
Exploit availability: No
DescriptionThe vulnerability allows a remote user to perform a denial of service (DoS) attack.
The vulnerability exists due to an off-by-one error in the SCSI device emulation in QEMU. A remote user on the guest OS can can trigger an off-by-one error while processing MODE SELECT commands in mode_sense_page() if the 'page' argument is set to MODE_PAGE_ALLS (0x3f). Successful exploitation of the vulnerability may result in QEMU crash.
Install updates from vendor's website.
Red Hat CodeReady Linux Builder for IBM z Systems: 8.0
Red Hat CodeReady Linux Builder for ARM 64: 8.0
Red Hat CodeReady Linux Builder for Power, little endian: 8.0
Red Hat CodeReady Linux Builder for x86_64: 8.0
Red Hat Enterprise Linux for ARM 64: 8
Red Hat Enterprise Linux for Power, little endian: 8
Red Hat Enterprise Linux for IBM z Systems: 8
Red Hat Enterprise Linux for x86_64: 8.0
CPE2.3- cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_ibm_z_systems:8.0:*:*:*:*:*:*:*
- cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_arm_64:8.0:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_power_little_endian:8.0:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_codeready_linux_builder_for_x86_64:8.0:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_arm_64:8:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_power_little_endian:8:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems:8:*:*:*:*:red_hat_enterprise_linux:*:*
- cpe:2.3:o:red_hat:red_hat_enterprise_linux:8.0:*:*:*:*:*:*:*
https://access.redhat.com/errata/RHSA-2021:5238
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the local network (LAN).
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
