#VU77502 Out-of-bounds write in Linux kernel - CVE-2023-35788

Vulnerability identifier: #VU77502

Vulnerability risk: Low

CVSSv4.0: 5.9 [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/E:U/U:Clear]

CVE-ID: CVE-2023-35788

CWE-ID: CWE-787

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error within the fl_set_geneve_opt() function in net/sched/cls_flower.c in Linux kernel. A local user can trigger an out-of-bounds write and execute arbitrary code with elevated privileges.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: before 6.3.7, 6.3.7

---

External links
https://www.openwall.com/lists/oss-security/2023/06/07/1
https://git.kernel.org/linus/4d56304e5827c8cc8cc18c75343d283af7c4825c
https://cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.3.7
https://www.openwall.com/lists/oss-security/2023/06/17/1
https://seclists.org/oss-sec/2023/q2/213

---

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.