cbcvebase.
CVE-2019-6109
published 2019-01-31

CVE-2019-6109: An issue was discovered in OpenSSH 7.9. Due to missing character encoding in the progress display, a malicious server (or Man-in-The-Middle attacker) can…

PriorityP184medium6.8CVSS 3.1
AVNACHPRNUIRSUCHIHAN
ITWVulnCheck KEVRansomware
Exploited in the wild
EPSS
3.81%
88.9th percentile
An issue was discovered in OpenSSH 7.9. Due to missing character encoding in the progress display, a malicious server (or Man-in-The-Middle attacker) can employ crafted object names to manipulate the client output, e.g., by using ANSI control codes to hide additional files being transferred. This affects refresh_progress_meter() in progressmeter.c.

Affected

41 ranges· showing 25
VendorProductVersion rangeFixed in
canonicalubuntu_linux
canonicalubuntu_linux
canonicalubuntu_linux
canonicalubuntu_linux
debiandebian_linux
debiandebian_linux
debianopenssh< openssh 1:7.9p1-6 (bookworm)openssh 1:7.9p1-6 (bookworm)
fedoraprojectfedora
fujitsum10-1_firmware< xcp2361xcp2361
fujitsum10-1_firmware< xcp3070xcp3070
fujitsum10-4_firmware< xcp2361xcp2361
fujitsum10-4_firmware< xcp3070xcp3070
fujitsum10-4s_firmware< xcp2361xcp2361
fujitsum10-4s_firmware< xcp3070xcp3070
fujitsum12-1_firmware< xcp2361xcp2361
fujitsum12-1_firmware< xcp3070xcp3070
fujitsum12-2_firmware< xcp2361xcp2361
fujitsum12-2_firmware< xcp3070xcp3070
fujitsum12-2s_firmware< xcp2361xcp2361
fujitsum12-2s_firmware< xcp3070xcp3070
openbsdopenssh<= 7.9
openbsdopenssh>= 0 < 1:7.9p1-61:7.9p1-6
openbsdopenssh>= 0 < 1:7.9p1-61:7.9p1-6
openbsdopenssh>= 0 < 1:7.9p1-61:7.9p1-6
openbsdopenssh>= 0 < 1:7.9p1-61:7.9p1-6

Detection & IOCsextracted from sources · hover to see the quote

  • The attack vector is crafted object/file names containing ANSI control codes sent by a malicious or MitM SSH server to manipulate the scp client's progress display output, hiding additional files being transferred.
  • The vulnerable code path is specifically in the refresh_progress_meter() function within progressmeter.c of the scp client. Focus dynamic analysis and code auditing on this function for missing character/ANSI encoding sanitization.
  • Only the scp binary (part of openssh-clients package) is affected, not the SSH protocol or ssh client itself. Detection should focus on scp sessions to untrusted or newly-keyed servers.
  • A change in the SSH host key of the server being connected to via scp can be an indicator of a MitM attack exploiting this vulnerability. Monitor for host key change warnings during scp sessions.
  • ·On Debian-based systems, the vulnerability is resolved in openssh package version 1:7.9p1-6. Ensure deployed versions meet or exceed this.
  • ·Red Hat Enterprise Linux 7 has marked this as 'Will not fix'. Operators on RHEL 7 should consider mitigating by removing the openssh-clients package if scp is not required.

CVSS provenance

nvdv3.16.8MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
nvdv2.04.0MEDIUMAV:N/AC:H/Au:N/C:P/I:P/A:N
osv6.8MEDIUM
vulncheck6.8MEDIUM
vendor_debian6.8MEDIUM
vendor_redhat6.8MEDIUM
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