CVE-2019-9162

Description

In the Linux kernel before 4.20.12, net/ipv4/netfilter/nf_nat_snmp_basic_main.c in the SNMP NAT module has insufficient ASN.1 length checks (aka an array index error), making out-of-bounds read and write operations possible, leading to an OOPS or local privilege escalation. This affects snmp_version and snmp_helper.

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

Debian

Security tracker ↗

Release	Package	Fixed in	Advisory
Debian 14	linux	4.19.28-1	—
Debian 13	linux	4.19.28-1	—
Debian 12	linux	4.19.28-1	—

Ubuntu

Security tracker ↗

Release	Package	Fixed in	Advisory
Ubuntu 18.04 LTS	linux-azure	4.18.0-1014.14~18.04.1	USN-3930-2
Ubuntu 18.04 LTS	linux-gcp-edge	4.18.0-1008.9~18.04.1	—
Ubuntu 18.04 LTS	linux-hwe	4.18.0-17.18~18.04.1	USN-3930-2

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

Exploit-DB 1

Linux < 4.14.103 / < 4.19.25 - Out-of-Bounds Read and Write in SNMP NAT Module EDB-46477 · dos · Mar 1, 2019 · verified

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Advisories 1

USN-3930-2 linux-hwe, linux-azure vulnerabilities Ubuntu Security Notices (USN) · Sep 7, 2026

In the Linux kernel before 4.20.12, net/ipv4/netfilter/nf_nat_snmp_basic_main.c in the SNMP NAT module has insufficient ASN.1 length checks…