Debian update for linux
| Risk | Medium |
| Patch available | YES |
| Number of vulnerabilities | 4 |
| CVE-ID | CVE-2020-36311 CVE-2021-3609 CVE-2021-33909 CVE-2021-34693 |
| CWE-ID | CWE-264 CWE-362 CWE-190 CWE-908 |
| Exploitation vector | Local |
| Public exploit |
Public exploit code for vulnerability #2 is available. Public exploit code for vulnerability #3 is available. |
| Vulnerable software Subscribe |
linux (Debian package) Operating systems & Components / Operating system package or component |
| Vendor | Debian |
Security Bulletin
This security bulletin contains information about 4 vulnerabilities.
1) Permissions, Privileges, and Access Controls
EUVDB-ID: #VU55262
Risk: Low
CVSSv3.1: 4.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]
CVE-ID: CVE-2020-36311
CWE-ID:
CWE-264 - Permissions, Privileges, and Access Controls
Exploit availability: No
DescriptionThe vulnerability allows a local user to perform a denial of service attack.
The vulnerability exists due to an error in arch/x86/kvm/svm/sev.c in Linux kernel, which allows soft lockup by triggering destruction of a large SEV VM (which requires unregistering many encrypted regions).
Update linux package to version 4.19.194-3.
Vulnerable software versionslinux (Debian package): 4.19.5-1~exp1 - 4.19.160-2
External linkshttp://www.debian.org/security/2021/dsa-4941
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
2) Race condition
EUVDB-ID: #VU54292
Risk: Medium
CVSSv3.1: 7.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C]
CVE-ID: CVE-2021-3609
Exploit availability: No
DescriptionThe vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a race condition in the CAN BCM networking protocol (net/can/bcm.c) in the Linux kernel ranging from version 2.6.25 to mainline 5.13-rc6. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.
MitigationUpdate linux package to version 4.19.194-3.
Vulnerable software versionslinux (Debian package): 4.19.5-1~exp1 - 4.19.160-2
External linkshttp://www.debian.org/security/2021/dsa-4941
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.
3) Integer overflow
EUVDB-ID: #VU55143
Risk: Low
CVSSv3.1: 7.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C]
CVE-ID: CVE-2021-33909
CWE-ID:
CWE-190 - Integer overflow
Exploit availability: Yes
DescriptionThe vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to integer overflow during size_t-to-int conversion when creating, mounting, and deleting a deep directory structure whose total path length exceeds 1GB. An unprivileged local user can write up to 10-byte string to an offset of exactly -2GB-10B below the beginning of a vmalloc()ated kernel buffer.
Successful exploitation of vulnerability may allow an attacker to exploit the our-of-bounds write vulnerability to execute arbitrary code with root privileges.
Update linux package to version 4.19.194-3.
Vulnerable software versionslinux (Debian package): 4.19.5-1~exp1 - 4.19.160-2
External linkshttp://www.debian.org/security/2021/dsa-4941
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.
4) Use of uninitialized resource
EUVDB-ID: #VU55263
Risk: Low
CVSSv3.1: 2.9 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]
CVE-ID: CVE-2021-34693
CWE-ID:
CWE-908 - Use of Uninitialized Resource
Exploit availability: No
DescriptionThe vulnerability allows a local user to gain access to sensitive information.
The vulnerability exists due to net/can/bcm.c in the Linux kernel through 5.12.10 allows local users to obtain sensitive information from kernel stack memory because parts of a data structure are uninitialized.
MitigationUpdate linux package to version 4.19.194-3.
Vulnerable software versionslinux (Debian package): 4.19.5-1~exp1 - 4.19.160-2
External linkshttp://www.debian.org/security/2021/dsa-4941
Q & A
Can this vulnerability be exploited remotely?
No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
