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Merged
aschackmull merged 4 commits into from
Jul 31, 2026
Merged

Actions: The regex wasn't escaping external input #22240

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b9a5dd4
The regex wasn't escaping external input
JarLob Jul 23, 2026
9c83964
Revalidate output clobbering expectations
JarLob Jul 31, 2026
c9727af
Merge remote-tracking branch 'github/main' into fix/actions-output-cl…
JarLob Jul 31, 2026
6c38d83
Merge branch 'main' into fix/actions-output-clobbering-regex
JarLob Jul 31, 2026
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5 changes: 4 additions & 1 deletion actions/ql/lib/codeql/actions/security/OutputClobberingQuery.qll
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Original file line number Diff line number Diff line change
Expand Up @@ -196,7 +196,10 @@ class WorkflowCommandClobberingFromFileReadSink extends OutputClobberingSink {
clobbering_cmd.regexpMatch(["ls", Bash::fileReadCommand()] + "\\s.*") and
(
// - run: echo "foo=$(<pr-id.txt)"
clobbering_stmt.regexpMatch("echo.*" + clobbering_cmd + ".*")
exists(string echo, int echoOffset |
echo = clobbering_stmt.regexpFind("\\becho\\s+", _, echoOffset) and
clobbering_stmt.indexOf(clobbering_cmd, 0, echoOffset + echo.length()) >= 0
)
or
// A file content is printed to stdout
// - run: cat pr-id.txt
Expand Down
4 changes: 4 additions & 0 deletions actions/ql/src/change-notes/2026-07-28-output-clobbering-regex.md
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@@ -0,0 +1,4 @@
---
category: fix
---
* Fixed a performance issue in the `actions/output-clobbering/high` query caused by using unescaped source-code input in a regular expression.
10 changes: 10 additions & 0 deletions actions/ql/test/query-tests/Security/CWE-074/.github/workflows/output2.yml
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Expand Up @@ -114,3 +114,13 @@ jobs:
run: |
# VULNERABLE: halt_error emits its input without JSON encoding
jq '.value | halt_error(1)' pr-number.json
- id: clob18
run: |
# VULNERABLE: the file name contains regex metacharacters
echo "VALUE=$(cat 'pr[number](final).txt')"
echo "::set-output name=OUTPUT::SAFE"
- id: clob19
run: |
# VULNERABLE: echo is invoked through env
env echo "VALUE=$(cat 'pr[number](final).txt')"
echo "::set-output name=OUTPUT::SAFE"
6 changes: 6 additions & 0 deletions actions/ql/test/query-tests/Security/CWE-074/OutputClobberingHigh.expected
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Expand Up @@ -16,6 +16,8 @@ edges
| .github/workflows/output2.yml:36:9:41:6 | Uses Step | .github/workflows/output2.yml:106:14:108:51 | # VULNERABLE: raw-output0 emits strings without JSON encoding\njq '.value' --raw-output0 pr-number.json\n | provenance | Config |
| .github/workflows/output2.yml:36:9:41:6 | Uses Step | .github/workflows/output2.yml:110:14:112:46 | # VULNERABLE: stderr emits its input without JSON encoding\njq '.value \| stderr' pr-number.json\n | provenance | Config |
| .github/workflows/output2.yml:36:9:41:6 | Uses Step | .github/workflows/output2.yml:114:14:116:53 | # VULNERABLE: halt_error emits its input without JSON encoding\njq '.value \| halt_error(1)' pr-number.json\n | provenance | Config |
| .github/workflows/output2.yml:36:9:41:6 | Uses Step | .github/workflows/output2.yml:118:14:121:48 | # VULNERABLE: the file name contains regex metacharacters\necho "VALUE=$(cat 'pr[number](final).txt')"\necho "::set-output name=OUTPUT::SAFE"\n | provenance | Config |
| .github/workflows/output2.yml:36:9:41:6 | Uses Step | .github/workflows/output2.yml:123:14:126:48 | # VULNERABLE: echo is invoked through env\nenv echo "VALUE=$(cat 'pr[number](final).txt')"\necho "::set-output name=OUTPUT::SAFE"\n | provenance | Config |
nodes
| .github/workflows/output1.yml:9:18:9:49 | github.event.comment.body | semmle.label | github.event.comment.body |
| .github/workflows/output1.yml:10:14:13:50 | # VULNERABLE\necho "OUTPUT_1=HARDCODED" >> $GITHUB_OUTPUT\necho "OUTPUT_2=$BODY" >> $GITHUB_OUTPUT\n | semmle.label | # VULNERABLE\necho "OUTPUT_1=HARDCODED" >> $GITHUB_OUTPUT\necho "OUTPUT_2=$BODY" >> $GITHUB_OUTPUT\n |
Expand All @@ -39,6 +41,8 @@ nodes
| .github/workflows/output2.yml:106:14:108:51 | # VULNERABLE: raw-output0 emits strings without JSON encoding\njq '.value' --raw-output0 pr-number.json\n | semmle.label | # VULNERABLE: raw-output0 emits strings without JSON encoding\njq '.value' --raw-output0 pr-number.json\n |
| .github/workflows/output2.yml:110:14:112:46 | # VULNERABLE: stderr emits its input without JSON encoding\njq '.value \| stderr' pr-number.json\n | semmle.label | # VULNERABLE: stderr emits its input without JSON encoding\njq '.value \| stderr' pr-number.json\n |
| .github/workflows/output2.yml:114:14:116:53 | # VULNERABLE: halt_error emits its input without JSON encoding\njq '.value \| halt_error(1)' pr-number.json\n | semmle.label | # VULNERABLE: halt_error emits its input without JSON encoding\njq '.value \| halt_error(1)' pr-number.json\n |
| .github/workflows/output2.yml:118:14:121:48 | # VULNERABLE: the file name contains regex metacharacters\necho "VALUE=$(cat 'pr[number](final).txt')"\necho "::set-output name=OUTPUT::SAFE"\n | semmle.label | # VULNERABLE: the file name contains regex metacharacters\necho "VALUE=$(cat 'pr[number](final).txt')"\necho "::set-output name=OUTPUT::SAFE"\n |
| .github/workflows/output2.yml:123:14:126:48 | # VULNERABLE: echo is invoked through env\nenv echo "VALUE=$(cat 'pr[number](final).txt')"\necho "::set-output name=OUTPUT::SAFE"\n | semmle.label | # VULNERABLE: echo is invoked through env\nenv echo "VALUE=$(cat 'pr[number](final).txt')"\necho "::set-output name=OUTPUT::SAFE"\n |
| .github/workflows/output3.yml:10:20:10:51 | github.event.comment.body | semmle.label | github.event.comment.body |
subpaths
#select
Expand All @@ -59,4 +63,6 @@ subpaths
| .github/workflows/output2.yml:106:14:108:51 | # VULNERABLE: raw-output0 emits strings without JSON encoding\njq '.value' --raw-output0 pr-number.json\n | .github/workflows/output2.yml:36:9:41:6 | Uses Step | .github/workflows/output2.yml:106:14:108:51 | # VULNERABLE: raw-output0 emits strings without JSON encoding\njq '.value' --raw-output0 pr-number.json\n | Attacker-controlled data printed to standard output may forge a `set-output` workflow command and overwrite step outputs in $@. | .github/workflows/output2.yml:106:14:108:51 | # VULNERABLE: raw-output0 emits strings without JSON encoding\njq '.value' --raw-output0 pr-number.json\n | this step |
| .github/workflows/output2.yml:110:14:112:46 | # VULNERABLE: stderr emits its input without JSON encoding\njq '.value \| stderr' pr-number.json\n | .github/workflows/output2.yml:36:9:41:6 | Uses Step | .github/workflows/output2.yml:110:14:112:46 | # VULNERABLE: stderr emits its input without JSON encoding\njq '.value \| stderr' pr-number.json\n | Attacker-controlled data printed to standard output may forge a `set-output` workflow command and overwrite step outputs in $@. | .github/workflows/output2.yml:110:14:112:46 | # VULNERABLE: stderr emits its input without JSON encoding\njq '.value \| stderr' pr-number.json\n | this step |
| .github/workflows/output2.yml:114:14:116:53 | # VULNERABLE: halt_error emits its input without JSON encoding\njq '.value \| halt_error(1)' pr-number.json\n | .github/workflows/output2.yml:36:9:41:6 | Uses Step | .github/workflows/output2.yml:114:14:116:53 | # VULNERABLE: halt_error emits its input without JSON encoding\njq '.value \| halt_error(1)' pr-number.json\n | Attacker-controlled data printed to standard output may forge a `set-output` workflow command and overwrite step outputs in $@. | .github/workflows/output2.yml:114:14:116:53 | # VULNERABLE: halt_error emits its input without JSON encoding\njq '.value \| halt_error(1)' pr-number.json\n | this step |
| .github/workflows/output2.yml:118:14:121:48 | # VULNERABLE: the file name contains regex metacharacters\necho "VALUE=$(cat 'pr[number](final).txt')"\necho "::set-output name=OUTPUT::SAFE"\n | .github/workflows/output2.yml:36:9:41:6 | Uses Step | .github/workflows/output2.yml:118:14:121:48 | # VULNERABLE: the file name contains regex metacharacters\necho "VALUE=$(cat 'pr[number](final).txt')"\necho "::set-output name=OUTPUT::SAFE"\n | Attacker-controlled data printed to standard output may forge a `set-output` workflow command and overwrite step outputs in $@. | .github/workflows/output2.yml:118:14:121:48 | # VULNERABLE: the file name contains regex metacharacters\necho "VALUE=$(cat 'pr[number](final).txt')"\necho "::set-output name=OUTPUT::SAFE"\n | this step |
| .github/workflows/output2.yml:123:14:126:48 | # VULNERABLE: echo is invoked through env\nenv echo "VALUE=$(cat 'pr[number](final).txt')"\necho "::set-output name=OUTPUT::SAFE"\n | .github/workflows/output2.yml:36:9:41:6 | Uses Step | .github/workflows/output2.yml:123:14:126:48 | # VULNERABLE: echo is invoked through env\nenv echo "VALUE=$(cat 'pr[number](final).txt')"\necho "::set-output name=OUTPUT::SAFE"\n | Attacker-controlled data printed to standard output may forge a `set-output` workflow command and overwrite step outputs in $@. | .github/workflows/output2.yml:123:14:126:48 | # VULNERABLE: echo is invoked through env\nenv echo "VALUE=$(cat 'pr[number](final).txt')"\necho "::set-output name=OUTPUT::SAFE"\n | this step |
| .github/workflows/output3.yml:10:20:10:51 | github.event.comment.body | .github/workflows/output3.yml:10:20:10:51 | github.event.comment.body | .github/workflows/output3.yml:10:20:10:51 | github.event.comment.body | Attacker-controlled data may inject or overwrite step outputs in $@. | .github/workflows/output3.yml:10:20:10:51 | github.event.comment.body | this action |
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