CVE-2019-14842
Publication date 26 November 2019
Last updated 24 July 2024
Ubuntu priority
Cvss 3 Severity Score
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.
Status
Package | Ubuntu Release | Status |
---|---|---|
libnbd | ||
18.04 LTS bionic | Not in release | |
16.04 LTS xenial | Not in release | |
14.04 LTS trusty | Not in release |
Severity score breakdown
Parameter | Value |
---|---|
Base score | 9.8 · Critical |
Attack vector | Network |
Attack complexity | Low |
Privileges required | None |
User interaction | None |
Scope | Unchanged |
Confidentiality | High |
Integrity impact | High |
Availability impact | High |
Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
References
Other references
- https://www.redhat.com/archives/libguestfs/2019-October/msg00060.html
- https://github.com/libguestfs/libnbd/commit/f75f602a6361c0c5f42debfeea6980f698ce7f09 (1.1.4)
- https://github.com/libguestfs/libnbd/commit/2c1987fc23d6d0f537edc6d4701e95a2387f7917 (stable-1.0)
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-14842
- https://www.cve.org/CVERecord?id=CVE-2019-14842