低危 Git for Visual Studio 远程执行代码漏洞

CVE编号

CVE-2021-21300

利用情况

POC 已公开

补丁情况

官方补丁

披露时间

2021-03-09

漏洞描述

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.

解决建议

建议您更新当前系统或软件至最新版，完成漏洞的修复。

参考链接
http://packetstormsecurity.com/files/163978/Git-LFS-Clone-Command-Execution.html
http://seclists.org/fulldisclosure/2021/Apr/60
http://www.openwall.com/lists/oss-security/2021/03/09/3
https://git-scm.com/docs/git-config
https://git-scm.com/docs/gitattributes
https://github.com/git/git/commit/684dd4c2b414bcf648505e74498a608f28de4592
https://github.com/git/git/security/advisories/GHSA-8prw-h3cq-mghm
https://lists.debian.org/debian-lts-announce/2022/10/msg00014.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedora...
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedora...
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedora...
https://lore.kernel.org/git/xmqqim6019yd.fsf%40gitster.c.googlers.com/
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-21300
https://security.gentoo.org/glsa/202104-01
https://support.apple.com/kb/HT212320

受影响软件情况

#	类型	厂商	产品	版本	影响面
1
	运行在以下环境
	应用	git-scm	git	*		Up to (including) 2.14.2
	运行在以下环境
	应用	git-scm	git	*	From (including) 2.17.0	Up to (excluding) 2.17.6
	运行在以下环境
	应用	git-scm	git	*	From (including) 2.18.0	Up to (excluding) 2.18.5
	运行在以下环境
	应用	git-scm	git	*	From (including) 2.19.0	Up to (excluding) 2.19.6
	运行在以下环境
	应用	git-scm	git	*	From (including) 2.20.0	Up to (excluding) 2.20.5
	运行在以下环境
	应用	git-scm	git	*	From (including) 2.21.0	Up to (excluding) 2.21.4
	运行在以下环境
	应用	git-scm	git	*	From (including) 2.22.0	Up to (excluding) 2.22.5
	运行在以下环境
	应用	git-scm	git	*	From (including) 2.23.0	Up to (excluding) 2.23.4
	运行在以下环境
	应用	git-scm	git	*	From (including) 2.24.0	Up to (excluding) 2.24.4
	运行在以下环境
	应用	git-scm	git	*	From (including) 2.25.0	Up to (excluding) 2.25.5
	运行在以下环境
	应用	git-scm	git	*	From (including) 2.26.0	Up to (excluding) 2.26.3
	运行在以下环境
	应用	git-scm	git	*	From (including) 2.29.0	Up to (excluding) 2.29.3
	运行在以下环境
	应用	git-scm	git	*	From (including) 2.30.0	Up to (excluding) 2.30.2
	运行在以下环境
	应用	git-scm	git	2.27.0	-
	运行在以下环境
	应用	git-scm	git	2.28.0	-
	运行在以下环境
	系统	alpine_3.10	git	*		Up to (excluding) 2.22.5-r0
	运行在以下环境
	系统	alpine_3.11	git	*		Up to (excluding) 2.24.4-r0
	运行在以下环境
	系统	alpine_3.12	git	*		Up to (excluding) 2.26.3-r0
	运行在以下环境
	系统	alpine_3.13	git	*		Up to (excluding) 2.30.2-r0
	运行在以下环境
	系统	alpine_3.14	git	*		Up to (excluding) 2.30.2-r0
	运行在以下环境
	系统	alpine_3.15	git	*		Up to (excluding) 2.30.2-r0
	运行在以下环境
	系统	alpine_3.16	git	*		Up to (excluding) 2.30.2-r0
	运行在以下环境
	系统	alpine_3.17	git	*		Up to (excluding) 2.30.2-r0
	运行在以下环境
	系统	alpine_3.18	git	*		Up to (excluding) 2.30.2-r0
	运行在以下环境
	系统	alpine_edge	git	*		Up to (excluding) 2.30.2-r0
	运行在以下环境
	系统	amazon_2	git	*		Up to (excluding) 2.23.4-1.amzn2.0.1
	运行在以下环境
	系统	amazon_AMI	git	*		Up to (excluding) 2.18.5-2.73.amzn1
	运行在以下环境
	系统	debian_10	git	*		Up to (excluding) 1:2.20.1-2+deb10u4
	运行在以下环境
	系统	debian_11	git	*		Up to (excluding) 1:2.30.2-1
	运行在以下环境
	系统	debian_12	git	*		Up to (excluding) 1:2.30.2-1
	运行在以下环境
	系统	debian_9	git	*		Up to (including) 2.11.0-3+deb9u7
	运行在以下环境
系统	debian_sid	git	*		Up to (excluding) 1:2.30.2-1
运行在以下环境
系统	fedora_32	perl-Git	*		Up to (excluding) 2.26.3-2.fc32
运行在以下环境
系统	fedora_33	perl-Git	*		Up to (excluding) 2.30.2-1.fc33
运行在以下环境
系统	fedora_34	git-instaweb	*		Up to (excluding) 2.30.2-1.fc34
运行在以下环境
系统	kylinos_loongarch64_V10SP1	git	*		Up to (excluding) 2.27.0-4.a.ky10
运行在以下环境
系统	opensuse_Leap_15.2	git-core	*		Up to (excluding) 2.26.2-lp152.2.6.1
运行在以下环境
系统	opensuse_Leap_15.3	perl-Git	*		Up to (excluding) 2.31.1-10.3.1
运行在以下环境
系统	suse_12_SP5	git-core	*		Up to (excluding) 2.26.2-27.43.1
运行在以下环境
系统	ubuntu_16.04	git	*		Up to (excluding) 1:2.7.4-0ubuntu1.10
运行在以下环境
系统	ubuntu_16.04.7_lts	git	*		Up to (excluding) 1:2.7.4-0ubuntu1.10
运行在以下环境
系统	ubuntu_18.04	git	*		Up to (excluding) 1:2.17.1-1ubuntu0.8
运行在以下环境
系统	ubuntu_18.04.5_lts	git	*		Up to (excluding) 1:2.17.1-1ubuntu0.8
运行在以下环境
系统	ubuntu_20.04	git	*		Up to (excluding) 1:2.25.1-1ubuntu3.1
运行在以下环境
系统	unionos_d	git	*		Up to (excluding) 1:2.20.1.4-deepin1

阿里云评分 3.1

• 攻击路径 远程
• 攻击复杂度 困难
• 权限要求 无需权限
• 影响范围 有限影响
• EXP成熟度 POC 已公开
• 补丁情况 官方补丁
• 数据保密性 数据泄露
• 数据完整性 无影响
• 服务器危害 无影响
• 全网数量 N/A

CWE-ID	漏洞类型
CWE-59	在文件访问前对链接解析不恰当（链接跟随）

Exp相关链接

• http://www.openwall.com/lists/oss-security/2021/03/09/3
• https://github.com/1uanWu/CVE-2021-21300
• https://github.com/AlkenePan/CVE-2021-21300
• https://github.com/CppXL/CVE-2021-21300
• https://github.com/erranfenech/CVE-2021-21300
• https://github.com/ETOCheney/cve-2021-21300
• https://github.com/Faisal78123/CVE-2021-21300
• https://github.com/Kirill89/CVE-2021-21300
• https://github.com/Maskhe/CVE-2021-21300

- avd.aliyun.com