NULL pointer dereference in Linux kernel - CVE-2019-12818

Vulnerability identifier: #VU19141

CSH Severity: Low

CVSS v4: 2.3 [CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2019-12818

CWE-ID: CWE-476

Exploitation vector: Adjecent network

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dreference error in the Linux kernel before 4.20.15 when processing NFC data. The error is triggered by the  nfc_llcp_build_tlv function in net/nfc/llcp_commands.c that may return NULL. Such behavior can lead to a NULL pointer dereference in the nfc_llcp_build_gb() function in net/nfc/llcp_core.c. A remote attacker can perform a denial of service (DoS) attack.

Linux kernel
Ubuntu
linux-kvm (Ubuntu package)
linux-snapdragon (Ubuntu package)
linux-hwe (Ubuntu package)
linux-gcp (Ubuntu package)
linux-azure (Ubuntu package)
linux (Ubuntu package)
linux-raspi2 (Ubuntu package)
linux-oem (Ubuntu package)
linux-oracle (Ubuntu package)
linux-gke-4.15 (Ubuntu package)

Install update from vendor's website.

Linux kernel - update to 4.20.15
linux-kvm (Ubuntu package) - update to 4.15.0-1042.42
linux-snapdragon (Ubuntu package) - update to 4.15.0-1060.66
linux-hwe (Ubuntu package) - update to 4.15.0-58.64~16.04.1
linux-gcp (Ubuntu package) - addressed in versions 4.15.0-1040.42~16.04.1, 4.15.0-1040.42
linux-azure (Ubuntu package) - update to 4.15.0-1055.60
linux (Ubuntu package) - update to 4.15.0-58.64
linux-raspi2 (Ubuntu package) - update to 4.15.0-1043.46
linux-oem (Ubuntu package) - update to 4.15.0-1050.57
linux-oracle (Ubuntu package) - addressed in versions 4.15.0-1021.23~16.04.1, 4.15.0-1021.23
linux-gke-4.15 (Ubuntu package) - update to 4.15.0-1040.42

• https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=58bdd544e2933a21a51eecf17c3f5f94038261b5
• https://github.com/torvalds/linux/commit/58bdd544e2933a21a51eecf17c3f5f94038261b5
• https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.20.15

• NULL pointer dereference in Linux kernel
• Ubuntu update for linux, linux-azure, linux-gcp and more