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CVE-2017-15994: Samba Rsync: Improper Validation of Integrity Check Value

CVE-2017-15994 is rated critical with a CVSS v3.0 base score of 9.8 and affects Samba Rsync. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

rsync 3.1.3-development before 2017-10-24 mishandles archaic checksums, which makes it easier for remote attackers to bypass intended access restrictions. NOTE: the rsync development branch has significant use beyond the rsync developers, e.g., the code has been copied for use in various GitHub projects.

Severity breakdown

CVSS v3.0 9.8: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
• Attack complexity: Low. No special conditions; the attack can be repeated reliably.
• Privileges required: None. No account or prior access is needed.
• User interaction: None. No action from any user is needed.
• Scope: Unchanged. Impact stays within the vulnerable component.
• Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
• Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
• Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-354: Improper Validation of Integrity Check Value

The product does not validate or incorrectly validates the integrity check values or checksums of a message.

Affected products

• Samba Rsync: up to and including 3.1.2

References

• https://git.samba.org/?p=rsync.git%3Ba=commit%3Bh=7b8a4ecd6ff9cdf4e5d3850ebf822f1e989255b3
• https://git.samba.org/?p=rsync.git%3Ba=commit%3Bh=9a480deec4d20277d8e20bc55515ef0640ca1e55
• https://git.samba.org/?p=rsync.git%3Ba=commit%3Bh=c252546ceeb0925eb8a4061315e3ff0a8c55b48b