vim/0001-patch-9.2.0357-security-command-injection-via-backti.patch
2026-05-21 13:24:31 +02:00

72 lines
2.3 KiB
Diff

From 7bad6e5ca6a40e80509a223cd6977ae949da15fc Mon Sep 17 00:00:00 2001
From: Christian Brabandt <cb@256bit.org>
Date: Wed, 15 Apr 2026 20:17:17 +0000
Subject: [PATCH] patch 9.2.0357: [security]: command injection via backticks
in tag files
Problem: [security]: command injection via backticks in tag files
(Srinivas Piskala Ganesh Babu, Andy Ngo)
Solution: Disallow backticks before attempting to expand filenames.
Github Advisory:
https://github.com/vim/vim/security/advisories/GHSA-cwgx-gcj7-6qh8
Supported by AI
Signed-off-by: Christian Brabandt <cb@256bit.org>
---
src/tag.c | 4 +++-
src/testdir/test_tagjump.vim | 22 ++++++++++++++++++++++
2 files changed, 25 insertions(+), 1 deletion(-)
diff --git a/src/tag.c b/src/tag.c
index f191fc5..7500616 100644
--- a/src/tag.c
+++ b/src/tag.c
@@ -4092,8 +4092,10 @@ expand_tag_fname(char_u *fname, char_u *tag_fname, int expand)
/*
* Expand file name (for environment variables) when needed.
+ * Disallow backticks, they could execute arbitrary shell
+ * commands. This is not needed for tag filenames.
*/
- if (expand && mch_has_wildcard(fname))
+ if (expand && mch_has_wildcard(fname) && vim_strchr(fname, '`') == NULL)
{
ExpandInit(&xpc);
xpc.xp_context = EXPAND_FILES;
diff --git a/src/testdir/test_tagjump.vim b/src/testdir/test_tagjump.vim
index 8b85bd6..fce4f14 100644
--- a/src/testdir/test_tagjump.vim
+++ b/src/testdir/test_tagjump.vim
@@ -1545,4 +1545,26 @@ func Test_tagbsearch()
set tags& tagbsearch&
endfunc
+" Test that backtick expressions in tag filenames are not expanded.
+" This prevents command injection via malicious tags files.
+func Test_tag_backtick_filename_not_expanded()
+ let pwned_file = 'Xtags_pwnd'
+ call assert_false(filereadable(pwned_file))
+
+ let tagline = "main\t`touch " .. pwned_file .. "`\t/^int main/;\"\tf"
+ call writefile([tagline], 'Xbt_tags', 'D')
+ call writefile(['int main(int argc, char **argv) {', '}'], 'Xbt_main.c', 'D')
+
+ set tags=Xbt_tags
+ sp Xbt_main.c
+
+ " The :tag command should fail to find the file, but must NOT execute
+ " the backtick shell command.
+ call assert_fails('tag main', 'E429:')
+ call assert_false(filereadable(pwned_file))
+
+ set tags&
+ bwipe!
+endfunc
+
" vim: shiftwidth=2 sts=2 expandtab
--
2.54.0