An issue was discovered in the Amazon Linux packages of OpenSSH 7.4 for Amazon Linux 1 and 2, because of an incomplete fix for CVE-2019-6111 within these specific packages. The fix had only covered cases where an absolute path is passed to scp. When a relative path is used, there is no verification that the name of a file received by the client matches the file requested. Fixed packages are available with numbers 7.4p1-22.78.amzn1 and 7.4p1-22.amzn2.0.2.
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.