Vulnerability in [Unknown] Libnbd
CVE-2019-14842
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.018 (78.8th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 79th percentile — 78.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.018 · newest: 0.018 · change: 0.000
Affected products
- [Unknown] Libnbd — versions 1.0.3
- Red Hat Libnbd
Weakness classification (CWE)
References
- bugzilla.redhat.com/show_bug.cgi (Third Party Advisory, Issue Tracking)
- www.redhat.com/archives/libguestfs/2019-October/msg00060.html (Patch, Third Party Advisory)
Frequently asked questions
- What is CVE-2019-14842?
- CVE-2019-14842 is a critical-severity vulnerability in [Unknown] Libnbd, classified under Incorrect Conversion between Numeric Types. CVSS score: 9.8/10. Published 2019-11-26.
- How severe is CVE-2019-14842?
- Critical severity. CVSS v3 base score is 9.8 out of 10.