CVE-2019-6111

Description

An issue was discovered in OpenSSH 7.9. Due to the scp implementation being derived from 1983 rcp, the server chooses which files/directories are sent to the client. However, the scp client only performs cursory validation of the object name returned (only directory traversal attacks are prevented). A malicious scp server (or Man-in-The-Middle attacker) can overwrite arbitrary files in the scp client target directory. If recursive operation (-r) is performed, the server can manipulate subdirectories as well (for example, to overwrite the .ssh/authorized_keys file).

CVSS breakdown

Affected products

• apache / mina_sshd2.2.0 – 2.2.0
• Canonical / Ubuntu Linux18.10 – 18.10
• Canonical / Ubuntu Linux14.04 – 14.04
• Canonical / Ubuntu Linux16.04 – 16.04
• Canonical / Ubuntu Linux18.04 – 18.04
• Debian / debian_linux9.0 – 9.0
• Debian / debian_linux8.0 – 8.0
• fedoraproject / fedora30 – 30
• FreeBSD / FreeBSD12.0 – 12.0
• FreeBSD / FreeBSD12.0 – 12.0
• FreeBSD / FreeBSD12.0 – 12.0
• FreeBSD / FreeBSD12.0
• FreeBSD / FreeBSD12.0 – 12.0
• Fujitsu / m10-1_firmwarexcp2361
• Fujitsu / m10-4_firmwarexcp2361
• Fujitsu / m10-4s_firmwarexcp2361
• Fujitsu / m12-1_firmwarexcp2361
• Fujitsu / m12-2_firmwarexcp2361
• Fujitsu / m12-2s_firmwarexcp2361
• OpenBSD / OpenSSH7.9
• RedHat / enterprise_linux7.0 – 7.0
• RedHat / enterprise_linux8.0 – 8.0
• RedHat / enterprise_linux_eus8.4 – 8.4
• RedHat / enterprise_linux_eus8.6 – 8.6
• RedHat / enterprise_linux_eus8.2 – 8.2
• RedHat / enterprise_linux_eus8.1 – 8.1
• RedHat / enterprise_linux_server_aus8.6 – 8.6
• RedHat / enterprise_linux_server_aus8.2 – 8.2
• RedHat / enterprise_linux_server_aus8.4 – 8.4
• RedHat / enterprise_linux_server_tus8.2 – 8.2
• RedHat / enterprise_linux_server_tus8.4 – 8.4
• RedHat / enterprise_linux_server_tus8.6 – 8.6
• Siemens / scalance_x204rna_eec_firmware3.2.7
• Siemens / scalance_x204rna_firmware3.2.7
• winscp / winscp5.1.3

Exploits & proofs of concept

• exploit-dbSCP Client - Multiple Vulnerabilities (SSHtranger Things)by Mark E. Haase
• exploit-dbOpenSSH SCP Client - Write Arbitrary Filesby Harry Sintonen

References

• VENDOR_ADVISORYhttps://www.debian.org/security/2019/dsa-4387
• MISChttps://security.netapp.com/advisory/ntap-20190213-0001/
• MISChttp://www.securityfocus.com/bid/106741
• MISChttps://cvsweb.openbsd.org/src/usr.bin/ssh/scp.c
• VENDOR_ADVISORYhttps://usn.ubuntu.com/3885-1/
• VENDOR_ADVISORYhttps://usn.ubuntu.com/3885-2/
• MISChttps://bugzilla.redhat.com/show_bug.cgi?id=1677794
• VENDOR_ADVISORYhttps://sintonen.fi/advisories/scp-client-multiple-vulnerabilities.txt
• EXPLOIThttps://www.exploit-db.com/exploits/46193/
• MISChttps://security.gentoo.org/glsa/201903-16
• MAILING_LISThttps://lists.debian.org/debian-lts-announce/2019/03/msg00030.html
• MAILING_LISThttp://www.openwall.com/lists/oss-security/2019/04/18/1
• MAILING_LISThttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/W3YVQ2BPTOVDCFDVNC2GGF5P5ISFG37G/
• MAILING_LISThttps://lists.apache.org/thread.html/c45d9bc90700354b58fb7455962873c44229841880dcb64842fa7d23%40%3Cdev.mina.apache.org%3E
• MAILING_LISThttps://lists.apache.org/thread.html/c7301cab36a86825359e1b725fc40304d1df56dc6d107c1fe885148b%40%3Cdev.mina.apache.org%3E
• MAILING_LISThttps://lists.apache.org/thread.html/e47597433b351d6e01a5d68d610b4ba195743def9730e49561e8cf3f%40%3Cdev.mina.apache.org%3E
• MAILING_LISThttp://lists.opensuse.org/opensuse-security-announce/2019-06/msg00058.html
• VENDOR_ADVISORYhttps://www.freebsd.org/security/advisories/FreeBSD-EN-19:10.scp.asc
• MAILING_LISThttps://lists.apache.org/thread.html/d540139359de999b0f1c87d05b715be4d7d4bec771e1ae55153c5c7a%40%3Cdev.mina.apache.org%3E
• VENDOR_ADVISORYhttps://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html
• VENDOR_ADVISORYhttps://access.redhat.com/errata/RHSA-2019:3702
• MAILING_LISThttp://www.openwall.com/lists/oss-security/2022/08/02/1
• MISChttps://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf