CVE-2019-9213

MEDIUM

Reliable Datagram Sockets (RDS) rds_atomic_free_op NULL pointer dereference Privilege Escalation

Title source: metasploit
STIX 2.1

Exploitation Summary

EIP tracks 3 public exploits for CVE-2019-9213. PoCs published by Metasploit, Google Security Research, Mohamed Ghannam, Jann Horn, wbowling, bcoles, nstarke, including Metasploit module exploits/linux/local/rds_atomic_free_op_null_pointer_deref_priv_esc.

AI-analyzed exploit summary This Metasploit module exploits a NULL pointer dereference in the `rds_atomic_free_op` function in the Linux kernel's RDS module (CVE-2018-5333) combined with a MAP_GROWSDOWN mmap_min_addr bypass (CVE-2019-9213) to achieve local privilege escalation on vulnerable Ubuntu 16.04 systems.

Description

In the Linux kernel before 4.20.14, expand_downwards in mm/mmap.c lacks a check for the mmap minimum address, which makes it easier for attackers to exploit kernel NULL pointer dereferences on non-SMAP platforms. This is related to a capability check for the wrong task.

Exploits (3)

exploitdb WORKING POC VERIFIED
by Metasploit · rubylocallinux
https://www.exploit-db.com/exploits/47957

This Metasploit module exploits a NULL pointer dereference in the `rds_atomic_free_op` function in the Linux kernel's RDS module (CVE-2018-5333) combined with a MAP_GROWSDOWN mmap_min_addr bypass (CVE-2019-9213) to achieve local privilege escalation on vulnerable Ubuntu 16.04 systems.

Classification
Working Poc 100%
Attack Type
Lpe
Complexity
Complex
Reliability
Reliable
Target: Linux kernel 4.4.0-116-generic and 4.8.0-54-generic on Ubuntu 16.04
Auth required
Prerequisites: Local access to a vulnerable Ubuntu 16.04 system · RDS kernel module loaded or not blacklisted · SMAP disabled
devstral-2 · analyzed Feb 16, 2026 Full analysis →
exploitdb WORKING POC VERIFIED
by Google Security Research · textdoslinux
https://www.exploit-db.com/exploits/46502

This exploit demonstrates a kernel NULL pointer dereference vulnerability (CVE-2019-9213) by mapping virtual address 0 on x86 systems without SMAP. It abuses a capability check flaw in `expand_downwards()` to bypass `dac_mmap_min_addr` restrictions, enabling exploitation of NULL pointer dereferences.

Classification
Working Poc 100%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: Linux Kernel (versions affected by CVE-2019-9213)
No auth needed
Prerequisites: x86 system without SMAP · ability to execute unprivileged code
devstral-2 · analyzed Feb 16, 2026 Full analysis →
metasploit WORKING POC GOOD
by Mohamed Ghannam, Jann Horn, wbowling, bcoles, nstarke · rubypoc
https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/linux/local/rds_atomic_free_op_null_pointer_deref_priv_esc.rb

This Metasploit module exploits a NULL pointer dereference in the `rds_atomic_free_op` function in the Linux kernel's RDS module (CVE-2018-5333) combined with a MAP_GROWSDOWN mmap_min_addr bypass (CVE-2019-9213) to achieve local privilege escalation on vulnerable Ubuntu 16.04 systems.

Classification
Working Poc 100%
Attack Type
Lpe
Complexity
Complex
Reliability
Reliable
Target: Linux kernel 4.4.0-116-generic and 4.8.0-54-generic (Ubuntu 16.04)
No auth needed
Prerequisites: RDS kernel module loaded or not blacklisted · 64-bit Ubuntu 16.04 system · SMAP disabled
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (26)

Core 26
Core References
Exploit, Third Party Advisory, VDB Entry exploit x_refsource_exploit-db
https://www.exploit-db.com/exploits/46502/
Mailing List, Patch, Vendor Advisory x_refsource_misc
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.162
Mailing List, Patch, Vendor Advisory x_refsource_misc
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.27
Mailing List, Patch, Vendor Advisory x_refsource_misc
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.105
Third Party Advisory, VDB Entry vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/107296
Exploit, Mailing List, Third Party Advisory x_refsource_misc
https://bugs.chromium.org/p/project-zero/issues/detail?id=1792
Mailing List, Patch, Vendor Advisory x_refsource_misc
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.20.14
Mailing List, Third Party Advisory mailing-list x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2019/03/msg00034.html
Mailing List, Third Party Advisory vendor-advisory x_refsource_suse
http://lists.opensuse.org/opensuse-security-announce/2019-03/msg00045.html
Mailing List, Third Party Advisory mailing-list x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2019/04/msg00004.html
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/3932-2/
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/3930-1/
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/3931-1/
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/3933-2/
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/3931-2/
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/3930-2/
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/3933-1/
Mailing List, Third Party Advisory vendor-advisory x_refsource_suse
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00052.html
Third Party Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2019:0831
Mailing List, Third Party Advisory mailing-list x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2019/05/msg00002.html
Third Party Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2019:1479
Third Party Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2019:1480
Third Party Advisory vendor-advisory x_refsource_ubuntu
https://usn.ubuntu.com/3932-1/

Scores

CVSS v3 5.5
EPSS 0.0693
EPSS Percentile 91.6%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Details

CWE
CWE-476
Status published
Products (10)
canonical/ubuntu_linux 12.04
canonical/ubuntu_linux 14.04
canonical/ubuntu_linux 16.04
canonical/ubuntu_linux 18.10
debian/debian_linux 8.0
linux/linux_kernel 4.9 - 4.9.162
opensuse/leap 15.0
opensuse/leap 42.3
redhat/enterprise_linux 7.0
redhat/enterprise_linux 8.0
Published Mar 05, 2019
Tracked Since Feb 18, 2026