CVE-2019-15239 Use after free in n/a
A local attacker can trigger use-after-free conditions in the Linux kernel TCP output handling, leading to privilege escalation or system crashes.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2019-15239?
CVE-2019-15239 is a high-severity use after free vulnerability in Debian Debian Linux, published on 20 Aug 2019. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, a certain net/ipv4/tcp_output.c change, which was properly incorporated into 4.16.12, was incorrectly backported to the earlier longterm kernels, introducing a new vulnerability that was potentially more severe than the issue that was intended to be fixed by backporting. Specifically, by adding to a write queue between disconnection and re-connection, a local attacker can trigger multiple use-after-free conditions. This can result in a kernel crash, or potentially in privilege escalation. NOTE: this affects (for example) Linux distributions that use 4.9.x longterm kernels before 4.9.190 or 4.14.x longterm kernels before 4.14.139.
Weakness: CWE-416
Which versions are affected by CVE-2019-15239?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2019-15239?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2019-15239 being exploited?
There is no known exploitation of CVE-2019-15239 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as DEBIAN-CVE-2019-15239, GHSA-7j8w-38v5-7qqp, UBUNTU-CVE-2019-15239.