CVE-2012-0809:sudo: Format-string vulnerability in sudo_debug
A reconstruction of the flaw, and the evidence path Lachesis follows to make it visible.
With no family and no line seeded, the whole-taxonomy enumerator put its class-matched lead inside sudo.c:1219 (sudo_debug) -- the sink CVE-2012-0809 is about and the.
That is the shape of the failure. The rest of this case file follows the evidence behind it.
What was known.
What Lachesis established.
Known before Lachesis ran
The CVE and vulnerable release were selected from public history. We are not claiming novel discovery.
- CVE
- CVE-2012-0809
- Vulnerable target
- SUDO_1_8_3 (last-vulnerable) · vulnerable
- Prior knowledge
- CVE-2012-0809 · SUDO_1_8_3 (last-vulnerable) is vulnerable
Independent re-detection
The experiment graph was built around the last-vulnerable release (SUDO_1_8_3), scoped to src + lib + include, so the vulnerable translation unit builds under the pass budget (build 7s, enrich 2844 nodes / 7372 edges), then enumerated BLIND over the whole constructor registry (no family hard-coded, no target line seeded). The census and candidate ids below are the enumerator's own verbatim output; prose in adjudication/trace is MY reading of the advisory + fix, clearly separated from tool output.
- Seeded inputs
- None
- Run timestamp
- 2026-09-03T00:00:00Z
- Evidence artifact
- cve-2012-0809.kuzu (built from sudo SUDO_1_8_3, scoped to src + lib + include; graph + sidecars deleted after capture)
The commands and outputs below come from this recorded Lachesis run.
What Lachesis reconstructed.
One historical repository. Four captured queries. A complete source-to-sink argument.
Lachesis follows the same evidence path through unfamiliar repositories.
Here is how the path becomes visible.
These are the recorded questions Lachesis asked of the historical vulnerable code, followed by the raw result and source location each query returned.
Captured runA real replay of Lachesis over the graph we built for this case (build 7s under the pass cap, bounded memory). Every value below is verbatim captured tool output; the graph was released immediately after capture.
Investigate the candidate
The narrowed scope builds the vulnerable TU under the pass cap.
build rc=0 7s
enrich rc=0 :: pass2 published 2844 nodes and 7372 edgesA small line with a large consequence.
the diagnostic path uses caller-influenced text (the program name) in a printf format position instead of a constant "%s" format, so any format specifier the attacker puts in argv[0] is interpreted.
/* sudo_debug: attacker-controlled program name used in a printf-family format position instead of a constant "%s" */
// 1.8.3p2 passes the untrusted program name through a fixed "%s" format instead of using it as the format string.
The original record.
Read the historical advisory and vulnerability record behind this reconstruction.