ALAS2-2021-1621

Related Vulnerabilities: CVE-2021-21300  

Git is an open-source distributed revision control system. In affected versions of Git a specially crafted repository that contains symbolic links as well as files using a clean/smudge filter such as Git LFS, may cause just-checked out script to be executed while cloning onto a case-insensitive file system such as NTFS, HFS+ or APFS (i.e. the default file systems on Windows and macOS). Note that clean/smudge filters have to be configured for that. Git for Windows configures Git LFS by default, and is therefore vulnerable. The problem has been patched in the versions published on Tuesday, March 9th, 2021. As a workaound, if symbolic link support is disabled in Git (e.g. via `git config --global core.symlinks false`), the described attack won't work. Likewise, if no clean/smudge filters such as Git LFS are configured globally (i.e. _before_ cloning), the attack is foiled. As always, it is best to avoid cloning repositories from untrusted sources. The earliest impacted version is 2.14.2. The fix versions are: 2.30.1, 2.29.3, 2.28.1, 2.27.1, 2.26.3, 2.25.5, 2.24.4, 2.23.4, 2.22.5, 2.21.4, 2.20.5, 2.19.6, 2.18.5, 2.17.62.17.6. (CVE-2021-21300)

ALAS2-2021-1621


Amazon Linux 2 Security Advisory: ALAS-2021-1621
Advisory Release Date: 2021-03-25 18:31 Pacific
Advisory Updated Date: 2021-03-25 20:53 Pacific
Severity: Medium
References: CVE-2021-21300 

Issue Overview:

Git is an open-source distributed revision control system. In affected versions of Git a specially crafted repository that contains symbolic links as well as files using a clean/smudge filter such as Git LFS, may cause just-checked out script to be executed while cloning onto a case-insensitive file system such as NTFS, HFS+ or APFS (i.e. the default file systems on Windows and macOS). Note that clean/smudge filters have to be configured for that. Git for Windows configures Git LFS by default, and is therefore vulnerable. The problem has been patched in the versions published on Tuesday, March 9th, 2021. As a workaound, if symbolic link support is disabled in Git (e.g. via `git config --global core.symlinks false`), the described attack won't work. Likewise, if no clean/smudge filters such as Git LFS are configured globally (i.e. _before_ cloning), the attack is foiled. As always, it is best to avoid cloning repositories from untrusted sources. The earliest impacted version is 2.14.2. The fix versions are: 2.30.1, 2.29.3, 2.28.1, 2.27.1, 2.26.3, 2.25.5, 2.24.4, 2.23.4, 2.22.5, 2.21.4, 2.20.5, 2.19.6, 2.18.5, 2.17.62.17.6. (CVE-2021-21300)


Affected Packages:

git


Issue Correction:
Run yum update git to update your system.

New Packages:
aarch64:
    git-2.23.4-1.amzn2.0.1.aarch64
    git-core-2.23.4-1.amzn2.0.1.aarch64
    git-daemon-2.23.4-1.amzn2.0.1.aarch64
    git-subtree-2.23.4-1.amzn2.0.1.aarch64
    git-debuginfo-2.23.4-1.amzn2.0.1.aarch64

i686:
    git-2.23.4-1.amzn2.0.1.i686
    git-core-2.23.4-1.amzn2.0.1.i686
    git-daemon-2.23.4-1.amzn2.0.1.i686
    git-subtree-2.23.4-1.amzn2.0.1.i686
    git-debuginfo-2.23.4-1.amzn2.0.1.i686

noarch:
    git-all-2.23.4-1.amzn2.0.1.noarch
    git-core-doc-2.23.4-1.amzn2.0.1.noarch
    git-cvs-2.23.4-1.amzn2.0.1.noarch
    git-email-2.23.4-1.amzn2.0.1.noarch
    gitk-2.23.4-1.amzn2.0.1.noarch
    gitweb-2.23.4-1.amzn2.0.1.noarch
    git-gui-2.23.4-1.amzn2.0.1.noarch
    git-instaweb-2.23.4-1.amzn2.0.1.noarch
    git-p4-2.23.4-1.amzn2.0.1.noarch
    perl-Git-2.23.4-1.amzn2.0.1.noarch
    perl-Git-SVN-2.23.4-1.amzn2.0.1.noarch
    git-svn-2.23.4-1.amzn2.0.1.noarch

src:
    git-2.23.4-1.amzn2.0.1.src

x86_64:
    git-2.23.4-1.amzn2.0.1.x86_64
    git-core-2.23.4-1.amzn2.0.1.x86_64
    git-daemon-2.23.4-1.amzn2.0.1.x86_64
    git-subtree-2.23.4-1.amzn2.0.1.x86_64
    git-debuginfo-2.23.4-1.amzn2.0.1.x86_64