CVE-2023-51767

2023-12-2400:00:00

ubuntu.com

138

openssh

row hammer attacks

authentication bypass

dram

threat model

user privileges

7 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

7 High

AI Score

Confidence

High

0.001 Low

EPSS

Percentile

20.2%

JSON

OpenSSH through 9.6, when common types of DRAM are used, might allow row
hammer attacks (for authentication bypass) because the integer value of
authenticated in mm_answer_authpassword does not resist flips of a single
bit. NOTE: this is applicable to a certain threat model of attacker-victim
co-location in which the attacker has user privileges.

Bugs

Notes

Author	Note
seth-arnold	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.
mdeslaur	The researchers used a modified version of sshd to make this vulnerability easier to demonstrate. There is no indication the openssh package in Ubuntu can be exploited in the same way. The upstream OpenSSH developers have chosen to ignore this issue as this vulnerability isn’t exploitable in practice, and needs to be addressed by the hardware platform, not in OpenSSH itself. Since there is nothing actionable here for Ubuntu, I am marking this issue as ignored.

Author

Note

seth-arnold

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.

mdeslaur

The researchers used a modified version of sshd to make this vulnerability easier to demonstrate. There is no indication the openssh package in Ubuntu can be exploited in the same way. The upstream OpenSSH developers have chosen to ignore this issue as this vulnerability isn’t exploitable in practice, and needs to be addressed by the hardware platform, not in OpenSSH itself. Since there is nothing actionable here for Ubuntu, I am marking this issue as ignored.