mirror of
https://github.com/ohmyzsh/ohmyzsh.git
synced 2024-11-25 01:03:41 +01:00
ef3f7c43a9
This lib function applies a patch to the VCS_INFO_formats function
in zsh versions from v5.0.3 until v5.8, which don't quote % chars
in some arguments received. Normally that just means that some
% characters in these strings (branch names, directories, etc.)
will be incorrectly parsed as formatting sequences.
With CVE-2021-45444, however, this means that one of these strings
from a malicious source (e.g. a malicious git repository) can
trigger command injection and run arbitrary code in the user's
machine when visiting such git repository.
Zsh 5.8.1 fixes this vulnerability [1], but older vcs_info setups
still need a workaround such as this one to patch the vulnerability.
[1] c3ea1e5d52
51 lines
2.3 KiB
Bash
51 lines
2.3 KiB
Bash
# Impacted versions go from v5.0.3 to v5.8 (v5.8.1 is the first patched version)
|
|
autoload -Uz is-at-least
|
|
if is-at-least 5.8.1 || ! is-at-least 5.0.3; then
|
|
return
|
|
fi
|
|
|
|
# Quote necessary $hook_com[<field>] items just before they are used
|
|
# in the line "VCS_INFO_hook 'post-backend'" of the VCS_INFO_formats
|
|
# function, where <field> is:
|
|
#
|
|
# base: the full path of the repository's root directory.
|
|
# base-name: the name of the repository's root directory.
|
|
# branch: the name of the currently checked out branch.
|
|
# misc: a string that may contain anything the vcs_info backend wants.
|
|
# revision: an identifier of the currently checked out revision.
|
|
# subdir: the path of the current directory relative to the
|
|
# repository's root directory.
|
|
#
|
|
# This patch %-quotes these fields previous to their use in vcs_info hooks and
|
|
# the zformat call and, eventually, when they get expanded in the prompt.
|
|
# It's important to quote these here, and not later after hooks have modified the
|
|
# fields, because then we could be quoting % characters from valid prompt sequences,
|
|
# like %F{color}, %B, etc.
|
|
#
|
|
# 32 │ hook_com[subdir]="$(VCS_INFO_reposub ${hook_com[base]})"
|
|
# 33 │ hook_com[subdir_orig]="${hook_com[subdir]}"
|
|
# 34 │
|
|
# 35 + │ for tmp in base base-name branch misc revision subdir; do
|
|
# 36 + │ hook_com[$tmp]="${hook_com[$tmp]//\%/%%}"
|
|
# 37 + │ done
|
|
# 38 + │
|
|
# 39 │ VCS_INFO_hook 'post-backend'
|
|
#
|
|
# This is especially important so that no command substitution is performed
|
|
# due to malicious input as a consequence of CVE-2021-45444, which affects
|
|
# zsh versions from 5.0.3 to 5.8.
|
|
#
|
|
autoload -Uz +X regexp-replace VCS_INFO_formats
|
|
|
|
# We use $tmp here because it's already a local variable in VCS_INFO_formats
|
|
typeset PATCH='for tmp (base base-name branch misc revision subdir) hook_com[$tmp]="${hook_com[$tmp]//\%/%%}"'
|
|
# Unique string to avoid reapplying the patch if this code gets called twice
|
|
typeset PATCH_ID=vcs_info-patch-9b9840f2-91e5-4471-af84-9e9a0dc68c1b
|
|
# Only patch the VCS_INFO_formats function if not already patched
|
|
if [[ "$functions[VCS_INFO_formats]" != *$PATCH_ID* ]]; then
|
|
regexp-replace 'functions[VCS_INFO_formats]' \
|
|
"VCS_INFO_hook 'post-backend'" \
|
|
': ${PATCH_ID}; ${PATCH}; ${MATCH}'
|
|
fi
|
|
unset PATCH PATCH_ID
|