CVE-2023-5215: Libnbd: crash or misbehaviour when nbd server returns an unexpected block size
A flaw was found in libnbd. A server can reply with a block size larger than 2^63 (the NBD spec states the size is a 64-bit unsigned value). This issue could lead to an application crash or other unintended behavior for NBD clients that doesn't treat the return value of the nbdgetsize() function correctly.
Other sources
In libnbd since v1.0 a server can reply with a block size larger than 2^63 (the NBD spec states size is a 64-bit unsigned value) possibly leading to application crash or other unintended behavior for NBD clients that doesn't treat the return value correctly.
References:
https://listman.redhat.com/archives/libguestfs/2023-September/032635.html
— Red Hat
Affected Software
Remediation
Event History
Frequently Asked Questions
What is CVE-2023-5215?
CVE-2023-5215 is a vulnerability found in libnbd that allows a server to reply with a block size larger than 2^63, leading to potential application crashes or unintended behavior for NBD clients.
What is the severity of CVE-2023-5215?
The severity of CVE-2023-5215 is medium, with a severity value of 5.3.
How does CVE-2023-5215 affect libnbd?
CVE-2023-5215 affects libnbd by allowing a server to respond with an oversized block size, which can cause issues in NBD clients that do not handle the returned value properly.
How can I fix CVE-2023-5215?
To fix CVE-2023-5215, update libnbd to version 1.18.0 or later, provided by the Red Hat package.
Where can I find more information about CVE-2023-5215?
You can find more information about CVE-2023-5215 in the following references: - [Red Hat Security Advisory](https://access.redhat.com/security/cve/CVE-2023-5215) - [Red Hat Bugzilla](https://bugzilla.redhat.com/show_bug.cgi?id=2241041) - [libguestfs Mailing List](https://listman.redhat.com/archives/libguestfs/2023-September/032635.html)