Denial of Service (DoS) Affecting libguestfs/libnbd package, versions [,1.0.3)


Severity

Recommended
0.0
critical
0
10

CVSS assessment by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.26% (50th percentile)

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  • Snyk IDSNYK-UNMANAGED-LIBGUESTFSLIBNBD-2365009
  • published26 Jan 2022
  • disclosed26 Nov 2019
  • creditUnknown

Introduced: 26 Nov 2019

CVE-2019-14842  (opens in a new tab)
CWE-681  (opens in a new tab)

How to fix?

Upgrade libguestfs/libnbd to version 1.0.3 or higher.

Overview

Affected versions of this package are vulnerable to Denial of Service (DoS). 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 Base Scores

version 3.1