SB2020123101 - Path traversal in Docker Docker

Description

This security bulletin contains information about 1 vulnerability.

1) Path traversal (CVE-ID: CVE-2020-27534)

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to perform directory traversal attacks.

The vulnerability exists due to util/binfmt_misc/check.go calls os.OpenFile with a potentially unsafe qemu-check temporary pathname, constructed with an empty first argument in an ioutil.TempDir call. A remote attacker can send a specially crafted HTTP request and read arbitrary files on the system.

Remediation

Install update from vendor's website.

References

• http://web.archive.org/web/20200530054359/
• https://docs.docker.com/engine/release-notes/
• https://github.com/moby/buildkit/pull/1462
• https://github.com/moby/moby/pull/40877
• https://golang.org/pkg/io/ioutil/#TempDir
• https://golang.org/pkg/os/#TempDir