CVE-2020-11008 Information

Description

Affected versions of Git have a vulnerability whereby Git can be tricked into sending private credentials to a host controlled by an attacker. This bug is similar to CVE-2020-5260(GHSA-qm7j-c969-7j4q). The fix for that bug still left the door open for an exploit where some credential is leaked (but the attacker cannot control which one). Git uses external \credential helper\ programs to store and retrieve passwords or other credentials from secure storage provided by the operating system. Specially-crafted URLs that are considered illegal as of the recently published Git versions can cause Git to send a \blank\ pattern to helpers missing hostname and protocol fields. Many helpers will interpret this as matching any URL and will return some unspecified stored password leaking the password to an attacker’s server. The vulnerability can be triggered by feeding a malicious URL to git clone. However the affected URLs look rather suspicious; the likely vector would be through systems which automatically clone URLs not visible to the user such as Git submodules or package systems built around Git. The root of the problem is in Git itself which should not be feeding blank input to helpers. However the ability to exploit the vulnerability in practice depends on which helpers are in use. Credential helpers which are known to trigger the vulnerability: - Git’s \store\ helper - Git’s \cache\ helper - the \osxkeychain\ helper that ships in Git’s \contrib\ directory Credential helpers which are known to be safe even with vulnerable versions of Git: - Git Credential Manager for Windows Any helper not in this list should be assumed to trigger the vulnerability.

CVSS Vector

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

Reference

http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00003.html http://seclists.org/fulldisclosure/2020/May/41 https://github.com/git/git/commit/c44088ecc4b0722636e0a305f9608d3047197282 https://github.com/git/git/security/advisories/GHSA-hjc9-x69f-jqj7 https://github.com/git/git/security/advisories/GHSA-qm7j-c969-7j4q https://lists.debian.org/debian-lts-announce/2020/04/msg00015.html https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/74Q7WVJ6FKLIN62VS2JD2XCNWK5TNKOW/ https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MOCTR2SEHCPSCOVUQJAGFPGKFMI2VE6V/ https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PN3FUOXKX3AXTULYV53ACABER2W2FSOU/ https://security.gentoo.org/glsa/202004-13 https://support.apple.com/kb/HT211183 https://usn.ubuntu.com/4334-1/

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

NONE

Base Score

NONE

Base Severity

7.5