CVE-2009-3623 Null dereference in n/a

What is CVE-2009-3623?

CVE-2009-3623 is a high-severity vulnerability in Linux kernel, published on 30 Oct 2009. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The lookup_cb_cred function in fs/nfsd/nfs4callback.c in the nfsd4 subsystem in the Linux kernel before 2.6.31.2 attempts to access a credentials cache even when a client specifies the AUTH_NULL authentication flavor, which allows remote attackers to cause a denial of service (NULL pointer dereference and system crash) via an NFSv4 mount request.

Weakness: CWE-287

Which versions are affected by CVE-2009-3623?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2009-3623?

No fix has been published for CVE-2009-3623 yet. Limit exposure of the affected software until one is available.

Is CVE-2009-3623 being exploited?

There is no known exploitation of CVE-2009-3623 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-4vrg-c54f-c5m9.