CVE-2020-12062 : The scp client in OpenSSH 8.2 incorrectly sends duplicate responses to the serve

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.

Published 2020-06-01 16:15:14

Updated 2024-08-04 12:15:43

Source MITRE

View at NVD, CVE.org

Products affected by CVE-2020-12062

Openbsd » Openssh » Version: 8.2
cpe:2.3:a:openbsd:openssh:8.2:*:*:*:*:*:*:*
Matching versions

Threat overview for CVE-2020-12062

Top countries where our scanners detected CVE-2020-12062

Top open port discovered on systems with this issue 22

IPs affected by CVE-2020-12062 8,047,740

Threat actors abusing to this issue? Yes

Find out if you^* are affected by CVE-2020-12062!

^*Directly or indirectly through your vendors, service providers and 3rd parties. Powered by attack surface intelligence from SecurityScorecard.

Exploit prediction scoring system (EPSS) score for CVE-2020-12062

EPSS FAQ

0.82%

Probability of exploitation activity in the next 30 days EPSS Score History

~ 72 %

Percentile, the proportion of vulnerabilities that are scored at or less

CVSS scores for CVE-2020-12062

Base Score	Base Severity	CVSS Vector	Exploitability Score	Impact Score	Score Source
5.0	MEDIUM	AV:N/AC:L/Au:N/C:N/I:P/A:N	10.0	2.9	NIST
Access Vector: Network Access Complexity: Low Authentication: None Confidentiality Impact: None Integrity Impact: Partial Availability Impact: None
7.5	HIGH	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N	3.9	3.6	NIST
Attack Vector: Network Attack Complexity: Low Privileges Required: None User Interaction: None Scope: Unchanged Confidentiality: None Integrity: High Availability: None

CWE ids for CVE-2020-12062

CWE-20 Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

Assigned by: nvd@nist.gov (Primary)

References for CVE-2020-12062

https://github.com/openssh/openssh-portable/commit/aad87b88fc2536b1ea023213729aaf4eaabe1894

upstream: when receving a file in sink(), be careful to send at · openssh/openssh-portable@aad87b8 · GitHub
Third Party Advisory
https://www.openssh.com/txt/release-8.3

Release Notes;Vendor Advisory
https://www.openwall.com/lists/oss-security/2020/05/27/1

oss-security - Announce: OpenSSH 8.3 released
Mailing List;Release Notes;Third Party Advisory
https://github.com/openssh/openssh-portable/commit/955854cafca88e0cdcd3d09ca1ad4ada465364a1

upstream: another case where a utimes() failure could make scp send · openssh/openssh-portable@955854c · GitHub
Patch;Third Party Advisory