#VU6526 Heap-out-of-bounds write in Linux kernel and linux_kernel (Debian package) - CVE-2017-7308

Vulnerability identifier: #VU6526

Vulnerability risk: Low

CVSSv4.0: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:A/U:Clear]

CVE-ID: CVE-2017-7308

CWE-ID: CWE-787

Exploitation vector: Local

Exploit availability: Yes

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system
linux_kernel (Debian package)
Operating systems & Components / Operating system package or component

Vendor: Linux Foundation
Debian

Description
The vulnerability allows a local attacker to cause DoS conditions.

The weakness exists due to improper validation of certain block-size data by the packet_set_ring function in net/packet/af_packet.c. A local attacker can provide specific parameters to the PACKET_RX_RING option on an AF_PACKET socket with a TPACKET_V3 ring buffer version enabled, trigger heap-out-of-bounds write and cause denial of service.

Successful exploitation of the vulnerability results in denial of service.

Mitigation
Update to version 4.9.18-1.

Vulnerable software versions

Linux kernel: 4.0.1 - 4.0.9, 4.1 - 4.10.6, 4.2.0 - 4.2.8, 4.3 - 4.3.6, 4.4.0 - 4.4.67, 4.5.0 - 4.5.7, 4.6 rc1 - 4.6.7, 4.7.0 - 4.7.10, 4.8.0 - 4.8.17, 4.9 - 4.9.27

linux_kernel (Debian package): 4.6.4-1 - 4.7.2-1

---

External links
https://googleprojectzero.blogspot.com/2017/05/exploiting-linux-kernel-via-packet.html

---

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, a fully functional exploit for this vulnerability is available.