Buffer overflow in Linux kernel - CVE-2020-8835
Published: March 31, 2020 / Updated: March 24, 2023
Vulnerability identifier: #VU26466
CSH Severity: Low
CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2020-8835
CWE-ID: CWE-119
Exploitation vector: Local access
Exploit availability:
Public exploit is available
Vulnerability details
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a boundary error in bpf verifier for 32 bit systems in Linux kernel. A local user can rigger a buffer overflow and gain access to sensitive information or execute arbitrary code on the system with elevated privileges.
Affected software
Linux kernel
Arch Linux
Fedora
kernel
kernel-headers
kernel-tools
Arch Linux
Fedora
kernel
kernel-headers
kernel-tools
How to mitigate CVE-2020-8835
Install updates from vendor's website.
As a temporary solution set the following sysctl:
kernel.unprivileged_bpf_disabled = 1
kernel - addressed in versions 5.5.15-100.fc30, 5.5.15-200.fc31, 5.5.16-100.fc30, 5.6.2-300.fc32
kernel-headers - addressed in versions 5.5.15-100.fc30, 5.5.15-200.fc31, 5.5.16-100.fc30
kernel-tools - addressed in versions 5.5.15-100.fc30, 5.5.15-200.fc31, 5.5.16-100.fc30
kernel-headers - addressed in versions 5.5.15-100.fc30, 5.5.15-200.fc31, 5.5.16-100.fc30
kernel-tools - addressed in versions 5.5.15-100.fc30, 5.5.15-200.fc31, 5.5.16-100.fc30
Links to Public Exploits and PoC-codes
- Exploit #8933 - INF8602-CVE-2020-8835 () (March 24, 2023)
- Exploit #7001 - CVE-2020-8835 () (November 11, 2021)
- Exploit #5542 - CVE-2020-8835-verification (Formal verification example for CVE-2020-8835) (June 9, 2021)
- Exploit #5168 - kernel-exploit-factory (Linux kernel CVE exploit analysis report and relative debug environment. You don't need to compile Linux kernel and configure your environment anymore. ) (February 23, 2021)
- Exploit #4925 - kernel_exploit_factory (Linux kernel CVE exploit analysis report and relative debug environment. You don't need to compile Linux kernel and configure your environment anymore. ) (December 11, 2020)
- Exploit #4856 - CVE-2020-8835 () (November 18, 2020)
- Exploit #4713 - CVE-2020-8835 () (October 18, 2020)
- Exploit #3471 - Rick_write_exp_CVE-2020-8835 () (July 15, 2020)
- Exploit #3024 - CVE-2020-8835 () (June 10, 2020)
- Exploit #2968 - IT19147192-CVE-2020-8835 () (June 3, 2020)
External References
Related Security Bulletins
- Privilege escalation in bpf in Linux kernel
- Arch Linux update for linux-lts
- Arch Linux update for Linux
- Arch Linux update for linux-hardened
- Arch Linux update for Linux
- Arch Linux update for linux-lts
- Arch Linux update for linux-hardened
- Fedora 32 update for kernel
- Fedora 31 update for kernel, kernel-headers, kernel-tools
- Fedora 30 update for kernel, kernel-headers, kernel-tools
- Fedora 30 update for kernel, kernel-headers, kernel-tools