CVE-2020-5260 - log back

CVE-2020-5260 edited at 15 Apr 2020 09:37:02
Description
- A flaw was found in git. Credentials can be leaked through the use of a crafted URL that contains a newline, fooling the credential helper to give information for a different host. Highest threat from the vulnerability is to data confidentiality.
+ Affected versions of Git have a vulnerability whereby Git can be tricked into sending private credentials to a host controlled by an attacker. 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 contain an encoded newline can inject unintended values into the credential helper protocol stream, causing the credential helper to retrieve the password for one server (e.g., good.example.com) for an HTTP request being made to another server (e.g., evil.example.com), resulting in credentials for the former being sent to the latter. There are no restrictions on the relationship between the two, meaning that an attacker can craft a URL that will present stored credentials for any host to a host of their choosing.
+ 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 problem has been patched in the versions published on April 14th, 2020, going back to v2.17.x. Anyone wishing to backport the change further can do so by applying commit 9a6bbee (the full release includes extra checks for git fsck, but that commit is sufficient to protect clients against the vulnerability). The patched versions are: 2.17.4, 2.18.3, 2.19.4, 2.20.3, 2.21.2, 2.22.3, 2.23.2, 2.24.2, 2.25.3, 2.26.1.
CVE-2020-5260 edited at 15 Apr 2020 09:34:18
References
+ https://github.com/git/git/security/advisories/GHSA-qm7j-c969-7j4q
+ https://lore.kernel.org/git/xmqqy2qy7xn8.fsf@gitster.c.googlers.com/
https://git.kernel.org/pub/scm/git/git.git/commit/?id=9a6bbee8006c24b46a85d29e7b38cfa79e9ab21b
https://git.kernel.org/pub/scm/git/git.git/commit/?id=c716fe4bd917e013bf376a678b3a924447777b2d
https://git.kernel.org/pub/scm/git/git.git/commit/?id=07259e74ec1237c836874342c65650bdee8a3993
https://bugs.chromium.org/p/project-zero/issues/detail?id=2021
CVE-2020-5260 edited at 15 Apr 2020 09:32:56
Notes
+ Mitigation
+ The most complete workaround is to disable credential helpers altogether:
+
+ git config --unset credential.helper
+ git config --global --unset credential.helper
+ git config --system --unset credential.helper
+
+ An alternative is to avoid malicious URLs:
+ 1. Examine the hostname and username portion of URLs fed to git clone for the presence of encoded newlines (%0a) or evidence of credential-protocol injections (e.g., host=github.com)
+ 2. Avoid using submodules with untrusted repositories (don't use clone --recurse-submodules; use git submodule update only after examining the URLs found in .gitmodules)
+ 3. Avoid tools which may run git clone on untrusted URLs under the hood
CVE-2020-5260 edited at 15 Apr 2020 07:17:40
Description
- Felix Wilhelm of Google Project Zero discovered a flaw in git, a fast, scalable, distributed revision control system. With a crafted URL that contains a newline, the credential helper machinery can be fooled to return credential information for a wrong host.
+ A flaw was found in git. Credentials can be leaked through the use of a crafted URL that contains a newline, fooling the credential helper to give information for a different host. Highest threat from the vulnerability is to data confidentiality.
CVE-2020-5260 edited at 14 Apr 2020 19:34:36
References
- https://github.com/git/git/commit/de49261b050d9cd8ec73842356077bc5b606640f
+ https://git.kernel.org/pub/scm/git/git.git/commit/?id=9a6bbee8006c24b46a85d29e7b38cfa79e9ab21b
+ https://git.kernel.org/pub/scm/git/git.git/commit/?id=c716fe4bd917e013bf376a678b3a924447777b2d
+ https://git.kernel.org/pub/scm/git/git.git/commit/?id=07259e74ec1237c836874342c65650bdee8a3993
https://bugs.chromium.org/p/project-zero/issues/detail?id=2021
CVE-2020-5260 edited at 14 Apr 2020 19:31:42
References
+ https://github.com/git/git/commit/de49261b050d9cd8ec73842356077bc5b606640f
https://bugs.chromium.org/p/project-zero/issues/detail?id=2021
CVE-2020-5260 created at 14 Apr 2020 19:17:03
Severity
+ High
Remote
+ Remote
Type
+ Information disclosure
Description
+ Felix Wilhelm of Google Project Zero discovered a flaw in git, a fast, scalable, distributed revision control system. With a crafted URL that contains a newline, the credential helper machinery can be fooled to return credential information for a wrong host.
References
+ https://bugs.chromium.org/p/project-zero/issues/detail?id=2021
Notes