Vulnerability Description
Structured reply is a feature of the newstyle NBD protocol allowing the server to send a reply in chunks. A bounds check which was supposed to test for chunk offsets smaller than the beginning of the request did not work because of signed/unsigned confusion. If one of these chunks contains a negative offset then data under control of the server is written to memory before the read buffer supplied by the client. If the read buffer is located on the stack then this allows the stack return address from nbd_pread() to be trivially modified, allowing arbitrary code execution under the control of the server. If the buffer is located on the heap then other memory objects before the buffer can be overwritten, which again would usually lead to arbitrary code execution.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Redhat | Libnbd | < 1.0.3 |
Related Weaknesses (CWE)
References
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-14842Issue TrackingThird Party Advisory
- https://www.redhat.com/archives/libguestfs/2019-October/msg00060.htmlPatchThird Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-14842Issue TrackingThird Party Advisory
- https://www.redhat.com/archives/libguestfs/2019-October/msg00060.htmlPatchThird Party Advisory
FAQ
What is CVE-2019-14842?
CVE-2019-14842 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Structured reply is a feature of the newstyle NBD protocol allowing the server to send a reply in chunks. A bounds check which was supposed to test for chunk offsets smaller than the beginning of the ...
How severe is CVE-2019-14842?
CVE-2019-14842 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2019-14842?
Check the references section above for vendor advisories and patch information. Affected products include: Redhat Libnbd.