CVE-2023-3338: Crash due to a null pointer dereference in the dn_nsp_send function
A flaw in the Linux Kernel found. While attempting to ping localhost by sending a Hello message to a local DECnet socket, Null Pointer Dereference happens in the dnnspsend function (net/decnet/dnnspout.c).
The bug happens only for systems where legacy code enabled (Kernel config param CONFIGDECNET), because the DECnet subsystem has been officially removed from all longterm and stable kernel series, starting from 4.14.319, 4.19.287, 5.4.248, 5.10.185 and 5.15.118.
Reference: https://seclists.org/oss-sec/2023/q2/276
Other sources
A null pointer dereference flaw was found in the Linux kernel's DECnet networking protocol. This issue could allow a remote user to crash the system.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 5.10.223-1Fixed in 5.10.234-1Fixed in 6.1.129-1Fixed in 6.1.133-1Fixed in 6.12.22-1 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 6.5 - Upgrade
Upgrade
Linux kernel (DECnet/CONFIG_DECNET)to a version that resolves this vulnerability.Fixed in 4.14.319 - Upgrade
Upgrade
Linux kernel (DECnet/CONFIG_DECNET)to a version that resolves this vulnerability.Fixed in 4.19.287 - Upgrade
Upgrade
Linux kernel (DECnet/CONFIG_DECNET)to a version that resolves this vulnerability.Fixed in 5.4.248 - Upgrade
Upgrade
Linux kernel (DECnet/CONFIG_DECNET)to a version that resolves this vulnerability.Fixed in 5.10.185 - Upgrade
Upgrade
Linux kernel (DECnet/CONFIG_DECNET)to a version that resolves this vulnerability.Fixed in 5.15.118 - Configuration
Disable legacy DECnet networking support (CONFIG_DECNET), since the issue triggers only when CONFIG_DECNET is enabled; DECnet is removed from longterm/stable kernel series starting from 4.14.319, 4.19.287, 5.4.248, 5.10.185 and 5.15.118.
Linux kernel CONFIG_DECNET = disabled - Compensating control
If you cannot update immediately, prevent remote triggering of the crash by blocking access to DECnet networking (legacy DECnet support) at the network layer; the flaw can be exploited remotely to crash the system.
Event History
Frequently Asked Questions
What is the severity of CVE-2023-3338?
CVE-2023-3338 is classified as a high-severity vulnerability due to its potential impact on systems with legacy DECnet protocols enabled.
How do I fix CVE-2023-3338?
To mitigate CVE-2023-3338, update the Linux kernel to version 6.5 or any of the specified remedied versions for Debian systems.
Who is affected by CVE-2023-3338?
CVE-2023-3338 affects systems running specific versions of the Linux kernel, particularly those with DECnet legacy code enabled.
What systems are at risk from CVE-2023-3338?
Systems at risk from CVE-2023-3338 include those using Red Hat and Debian distributions with kernel versions prior to 6.5.
What type of issue is CVE-2023-3338?
CVE-2023-3338 is a null pointer dereference vulnerability occurring in the dn_nsp_send function of the Linux kernel.