Commit Graph
6 Commits
Author SHA1 Message Date
Marius CiepluchandClaude Opus 5 1ce7e9db9b fix(cpg): build php through the frontend and retry while it drops files
The intermittent empty-graph builds that cost four manual retries to measure
WP Statistics at all.

First, a correction: the explanation this repo carried was wrong. It said
php-parse's stderr banners interleave into block-buffered stdout and corrupt
the JSON. Capturing the exact bytes php2cpg receives -- by putting a logging
wrapper on `php` -- shows its input arriving complete and valid: two
well-formed JSON documents, 5,176,594 bytes, byte-identical across runs, with
no banner anywhere inside them. The defect is in php2cpg's own reading of that
input, and nothing outside it repairs a given attempt.

Three fixes were tried against the old theory and each changed nothing, which
is how the theory died:

  * an unbuffered PHP shim via --php-parser-bin        0 of 6 builds usable
  * compacting the JSON, 5,176,594 -> 943,028 bytes    0 of 6
  * -J-Djava.util.concurrent.ForkJoinPool.common.parallelism=1   0 of 6

What is true is that the failure is INTERMITTENT, and that `joern-parse` is
both worse at it and silent about it. Measured on one WordPress slice:

    joern-parse   5 of 8 builds usable, and says nothing when they are not
    php2cpg      11 of 12 builds usable, and names every file it dropped

So php builds through the frontend directly and retries while it reports
dropped files. Retrying is sound only because the failure is intermittent AND
reported -- retrying a silent failure would be superstition; retrying a
reported one is just using the report. It gives up after four attempts and
reports what is still missing rather than pretending a partial graph is whole.

    wp-vuln through the driver   before: 4+ manual retries to get one build
                                 after:  6 of 6, 3 entailed findings each time

joern-parse remains the path for every other language, and the fallback when
no frontend is on PATH.

843 tests pass; gates byte-identical; mwwpform, pmpro and VAmPI unchanged.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
2026-09-09 21:11:12 +02:00
Marius CiepluchandClaude Opus 5 d6908f18ba feat(cpg): the hook half — CVE-2022-25148 found across an add_filter/apply_filters edge
The last of the three WordPress flaw classes 5.8 measured as missed. The
value crosses a registry inside WordPress core:

    add_filter('wp_statistics_current_page', array($this, 'set_current_page'));
    return apply_filters('wp_statistics_current_page', $current_page);

php2cpg drops the callback argument entirely -- the CPG holds
`add_filter("wp_statistics_current_page", )` -- so the edge cannot come from
the graph at any price. It comes from the source text instead, where both ends
are literals, via `mapping.php_hook_callbacks`.

                 vulnerable                              fixed
  wpstatistics   3 entailed, incl. pages.php:225:record  2, that one absent
  mwwpform       1 ($this->attachments)                  0
  pmpro          18, incl. CVE at :936                   1
  VAmPI          4                                       unchanged

The correctly-prepared sibling query one line below the CVE is not flagged on
either side.

Four things this cost, each measured rather than guessed:

  * Half one must be asked per ARRAY KEY, not per callback. "Does an
    unsanitized value reach this callback's return" is TRUE on both sides: the
    fix escapes `type` and `id` and leaves `search_query` alone. A
    callback-level answer flags the fixed side as readily as the vulnerable
    one, which is a leak, not a detection. The key is a literal at both ends,
    so it joins the way the hook name and the field name do -- the same idea
    for the third time.

  * The sanitizer test had to stop crediting a sibling's cleansing. The
    vulnerable query is ONE concatenation holding both `esc_sql($page_uri)`
    and the injectable `{$current_page['id']}`, so asking whether a
    sanitizer's name appears in a path element's text marked the whole flow
    sanitized. An element must now BE the cleansing -- a call to it, or its
    name as a string literal, which keeps `array_map('esc_sql', ...)` working.

  * Hook seeds are repository-wide where field seeds are file-scoped. A hook
    registry is global by construction: the callback is in one file and its
    `apply_filters` in another. The query returned nothing until those two
    scopes were separated.

  * `sourceKind` had to be REPORTED, not inferred. By the time a row reaches
    Python a hook source reads as `$current_page["id"]` and a parameter as
    `$args`, and `_usable_flows` discards parameter flows whenever a modelled
    one is present -- so seven sanitized `$_SERVER["REQUEST_URI"]` flows
    displaced the CVE between the query and the verdict. That preference then
    had to move PER SINK SITE: applied across a region it decides one site's
    question with another site's evidence, and PMPro's CVE at :936 vanished
    from a region still reporting fifteen other findings.

`verdict` now delegates to `verdicts` rather than running its own selection
over the union, because two copies of "which flow decides" is exactly the
duplication this module has been bitten by before -- and had been again: the
per-site preference did not reach the single-verdict path, so the two entry
points disagreed about the same rows.

841 tests pass; gates byte-identical; VAmPI unchanged.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
2026-09-09 20:42:35 +02:00
Marius CiepluchandClaude Opus 5 dcdbe322a1 feat(cpg): taint a field where it is assigned — the field half of 5.11
`_delete_files()` takes no parameters. CVE-2023-6559 arrives as a FIELD,
written by one method and read by another:

    public function __construct( ..., array $attachments = array() )
        $this->attachments = $attachments;          // half one ends here
    protected function _delete_files()
        foreach ( $this->attachments as $file )     // half two starts here
            unlink( $file );

Both halves were already in the graph. Only the join was missing, and the key
it joins on is the literal `$this->attachments`, written identically at both
ends -- so this is a second question asked with the query that already exists,
not an edge a frontend has to invent.

A read of `$this->F` is a source when some assignment to the same literal
`$this->F` in the same file is fed by an unsanitized flow from a seed. Scoped
three ways so a field name common to every class ever written cannot become a
wormhole: only fields the sink scope reads, only assignments in the same file,
and the right-hand side must itself be reachable from a source.

The receiver could then leave `parameterNodes` -- the precision fix refused
two commits ago, now sound, because the path it was standing in for is carried
by the field it actually travels through:

                          before                     after
  mwwpform vulnerable     1, from `this`             1, from $this->attachments
  mwwpform fixed          0                          0
  pmpro vulnerable        15 -- 4 named, 11 receiver 18 -- all named or field
  pmpro fixed             1, receiver-sourced        1
  VAmPI                   4 entailed                 4 entailed, unchanged

CVE-2023-23488 is still at class.memberorder.php:936 and CVE-2023-6559 at
class.mail.php:259. Every finding now names the value it followed instead of
naming the object.

Three things cost a measurement each, recorded in the task:

  * A summary must carry the SANITIZATION status of the half it summarises,
    not merely its reachability. Without that clause,
    `$this->sqlQuery = "..." . esc_sql($x) . "..."` reads as tainted -- and
    PMPro builds most of its queries that way, so the fixed side went from 1
    finding to 13. That is the pair no longer separating, which is the only
    number that matters.
  * Two-phase `reachableBy` then `reachableByFlows` is SLOWER, not faster:
    183s -> 256s. Running the analysis twice costs more than skipping path
    reconstruction saves. Reverted.
  * Memoizing per field rather than per file took it to 97s, about 1.6x the
    pre-field cost for that class, because only fields some region reads are
    worth the flow query.

`inScope` is factored out of `sinkCalls` so the field sources are scoped to
exactly the same place as the sinks, rather than a second copy of those three
branches drifting from the first.

841 tests pass; gates byte-identical; VAmPI unchanged.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
2026-09-09 19:42:20 +02:00
Marius CiepluchandClaude Opus 5 e41d6dd7ea docs(contributor-scan): 5.11 -- a detection strategy, not a verdict of impossible
"Structurally impossible" is a verdict, and a verdict is not a plan. Replacing
both structural-miss tasks with the one mechanism that covers them, because
they are the same shape: two halves of a path joined by a key that is a
literal in the source text.

    hook:   $_REQUEST -> ... -> return of set_current_page
            key: 'wp_statistics_current_page'   literal at both ends
            return of apply_filters(key) -> ... -> $wpdb->get_row

    field:  $_POST -> ... -> assignment to $this->attachments
            key: attachments                    a field name at both ends
            read of $this->attachments -> ... -> unlink

Neither half is missing from the graph. Only the join is. So this is not a
request for a frontend to draw an edge it cannot draw -- it is a second
question asked with the query that already exists:

  stage 1  the existing taint question against a synthetic endpoint: does
           untrusted data reach a callback's return, or an assignment to
           $this->F?
  table    built by reading literals, never inferring: add_filter('H', c)
           against apply_filters('H', ...); $this->F = against $this->F
  stage 2  does the apply_filters return, or the field read, reach a sink?
  join     on the key, with the RUNG carrying the join's uncertainty -- one
           registered callback and a literal key entails; several callbacks or
           a computed hook name corroborates, and the witness says which

"Any hook may reach any handler" is refused absolutely: a complete graph over
the plugin would entail everything.

No new dependency, no CPG mutation, no IR -- both stages ride the batch that
already runs, which is the point of expressing it as a query-level join.

It also recovers the precision fix 5.8 had to refuse. With the field half
working, _delete_files() is reached through $this->attachments rather than
through $this being tainted wholesale, so the receiver can then leave
parameter sources and take PMPro's 11 receiver-sourced findings with it.
5.8's numbers are the before-side of that measurement, and both observables
are pairs already pinned.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
2026-09-09 18:45:55 +02:00
Marius CiepluchandClaude Opus 5 435c14f3ec docs(contributor-scan): 5.8 -- WordPress class by class, including what it cannot ask
Three plugins, each pinned at a version whose advisory was read out of the
code, each measured against its own fixed commit:

  unauth injection, sink in the receiving function  pmpro        FOUND
  arbitrary file operation                          mwwpform     FOUND
  unauth injection across a WordPress hook          wpstatistics MISSED
  missing capability check                          --           cannot be asked
  unescaped output                                  --           cannot be trusted

Both hits are entailed by the graph alone -- no judge, no spend -- and both
disappear on the fixed side, because both fixes are calls the fact tables
carry: `$wpdb->prepare` and `realpath()`. The engine is not recognising a bug;
it is failing to find a cleansing call on a path it resolved, then finding one.

Precision is stated rather than flattered. PMPro's vulnerable side reports 15
entailed, 4 from a named parameter and 11 from the receiver, and one of those
survives into 2.9.8 at a query whose every fragment is `esc_sql`-wrapped.

The miss is the useful half, and it is checkable rather than inferred. WP
Statistics' CVE has a modelled source, a modelled sink and `esc_sql` as its
fix, and reports nothing on either side, because the file holding the sink has
zero superglobals, makes no call into the class holding the source, and is
joined to it only by

    add_filter('wp_statistics_current_page', array($this, 'set_current_page'));
    return apply_filters('wp_statistics_current_page', $current_page);

Both ends name the callback with a string, so no frontend can draw the edge.
Most plugin data travels this way. What the engine reports there instead is two
other sites, the same class at the wrong lines, identical on both sides -- and
not noise: upstream annotates both `// phpcs:ignore WordPress.DB.PreparedSQL`
and later rewrote one with `$wpdb->prepare`.

Two classes could not be asked at all, which is not the same as a miss.
`dominance_specs(language="php")` is empty, so missing-capability is never
asked; and `output_encoding` shares the one flat sanitizer list, which holds
`esc_sql` and `intval` but not `esc_html` -- wrong in both directions, so no
XSS verdict from this engine currently means anything.

5.10's root cause is recorded too: php2cpg's parser bridge, a race rather than
a scale limit, and the mitigation is per-file exclusion. Adds 5.11 (the hook
edge, with CVE-2022-25148 as its observable) and 5.12 (taint a field where it
is assigned, with CVE-2023-6559 as its guard).

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
2026-09-09 18:36:00 +02:00
Marius CiepluchandClaude Opus 5 8c387306be feat(repos): pinned known-vulnerable checkouts, offline by default
The pair corpus scores excerpts: a vulnerable function and its fixed twin,
handed to the engine with the answer already narrowed down. Nothing in it
exercises a repository -- region ranking, the budget, one CPG over
thousands of files, or whether a verdict that holds on fifteen lines still
holds when the source, the sink and the guard live in three modules.

benchmarks/repos/<name>.toml names a real checkout: url, a full 40-char
commit SHA, licence, and every known vulnerability with its file, function
and line. `ousast repos` lists them; `--fetch` materialises one; CI does
neither, and conftest clears the switch and redirects the cache so a
developer with warm checkouts cannot read them by accident.

Three rules the loader enforces rather than documents:

- A branch or tag is rejected. Either would make the same recipe mean
  different code next month while the baseline it produced kept the old
  numbers.
- `in_scope` must be stated per vulnerability, never defaulted. It decides
  whether "not found" is a miss or a non-question, which is the most
  important thing about the result.
- A recipe that declares `detection` must name something in scope to
  detect.

`ousast repos` does not trust a recipe either: against a materialised
checkout it checks HEAD against the pin, that the licence file is there,
and that each declared function appears above its declared line. That
earned its place immediately -- the first libpng recipe named LICENSE.md,
which is the filename at HEAD today and not at the pinned commit, where it
is still LICENSE.

Two checkouts, verified against the real repositories:

- vampi (MIT, 520 lines) is the DETECTION checkout. Excerpts of it are
  already in the pair corpus, including the update_password miss diagnosed
  earlier, so a whole-repository run says directly whether a verdict
  survives the move off the excerpt. Its routes register through an
  OpenAPI operationId, so it exercises registration-based entry-point
  mapping rather than the decorator path.
- libpng (libpng-2.0, 91k lines of C) is the ENVELOPE checkout, pinned at
  the parent of the commit that added the missing clamp. Its CVE is marked
  out of scope: an out-of-bounds read is not a family this engine
  arbitrates, and recording "not found" against it as a miss is the
  easiest way to make a measurement lie.

Nothing is vendored; the recipe records the licence so an artifact can say
what it ran against.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG
2026-09-09 08:10:59 +02:00