CVE-2020-12062

Published: 1 June 2020

** DISPUTED ** The scp client in OpenSSH 8.2 incorrectly sends duplicate responses to the server upon a utimes system call failure, which allows a malicious unprivileged user on the remote server to overwrite arbitrary files in the client's download directory by creating a crafted subdirectory anywhere on the remote server. The victim must use the command scp -rp to download a file hierarchy containing, anywhere inside, this crafted subdirectory. NOTE: the vendor points out that "this attack can achieve no more than a hostile peer is already able to achieve within the scp protocol" and "utimes does not fail under normal circumstances."

Notes

openssh-ssh1 is provided for compatibility with old devices that
cannot be upgraded to modern protocols. Thus we may not provide security
support for this package if doing so would prevent access to equipment.

this issue has been disputed as being a security issue, we will
not be fixing this issue in Ubuntu.

Status

Severity score breakdown

References

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-12062
• https://www.openssh.com/txt/release-8.3
• https://www.openwall.com/lists/oss-security/2020/05/27/1
• NVD
• Launchpad
• Debian