#VU28180 NULL pointer dereference in Linux kernel - CVE-2020-10711
Vulnerability identifier: #VU28180
Vulnerability risk: Medium
CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]
CVE-ID:
CWE-ID:
CWE-476
Exploitation vector: Network
Exploit availability: No
Vulnerable software:
Linux kernel
Operating systems & Components /
Operating system
Vendor: Linux Foundation
Description
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in the Linux kernel's SELinux subsystem when importing the Commercial IP Security Option (CIPSO) protocol's category bitmap into the SELinux extensible bitmap via the' ebitmap_netlbl_import' routine. While processing the CIPSO restricted bitmap tag in the 'cipso_v4_parsetag_rbm' routine, it sets the security attribute to indicate that the category bitmap is present, even if it has not been allocated.
A remote attacker can send specially crafted packets the affected system, trigger a NULL pointer dereference error and crash the Linux kernel.
Mitigation
Install updates from vendor's website.
Vulnerable software versions
Linux kernel: 2.6_test9_cvs - 2.6.39.4, 3.10 - 3.10.107, 4.18 - 4.18.20, 5.0 - 5.0.21
External links
https://www.openwall.com/lists/oss-security/2020/05/12/2
https://access.redhat.com/security/cve/cve-2020-10711
https://bugzilla.redhat.com/show_bug.cgi?id=1825116
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4b8feff251da3d7058b5779e21b33a85c686b974
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.
