Risk | Medium |
Patch available | YES |
Number of vulnerabilities | 1 |
CVE-ID | CVE-2021-33909 |
CWE-ID | CWE-190 |
Exploitation vector | Local |
Public exploit | Public exploit code for vulnerability #1 is available. |
Vulnerable software Subscribe |
Linux kernel Operating systems & Components / Operating system |
Vendor |
Security Bulletin
This security bulletin contains one medium risk vulnerability.
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.
Install updates from vendor's website.
Vulnerable software versionsLinux kernel: before 5.13.4
External linkshttp://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13.4
http://github.com/torvalds/linux/commit/8cae8cd89f05f6de223d63e6d15e31c8ba9cf53b
http://www.openwall.com/lists/oss-security/2021/07/20/1
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.