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
Pinned known-vulnerable checkouts
The pair corpus scores excerpts: a vulnerable function and its fixed twin, fifteen lines each, handed to the engine with the answer already narrowed down. That measures arbitration. It cannot measure anything about a repository — region ranking, the budget, one CPG over thousands of files, or whether a verdict that holds on an excerpt still holds when the source, the sink and the guard live in three different modules.
These recipes name real checkouts so those questions can be measured instead of assumed.
What a recipe is
One TOML file per repository, naming a url, a full 40-character commit SHA, the licence, and every known vulnerability with the file, function and line it lives at.
ousast repos # what is pinned, and whether it is checked out
ousast repos --repo vampi --fetch # materialise one (network; CI never does this)
ousast repos --json # the same, for an artifact
Nothing here is vendored. The repositories stay in their own projects under their own licences; the recipe records the licence so a measurement artifact can say what it ran against.
Three rules, and why
Offline by default. A recipe is inert until someone asks for the network — --fetch for one run, or
OPENULTRASAST_REPOS_NETWORK=1. CI sets neither, and the test suite clears both. This is the same rule the
pointer pairs follow, for the same reason: a test suite that quietly reaches the network is a test suite that
fails for reasons that have nothing to do with the code.
Pinned, not tracked. commit must be a full SHA; a branch or a tag is rejected at load. A tag gets
re-cut and a branch moves every week, and either would make the same recipe mean different code next month
while the baseline it produced still carried the old numbers.
A recipe declares what it can measure. measures is detection, envelope, or both, and every known
vulnerability states in_scope explicitly — whether it belongs to a family this engine arbitrates at all.
There is no default, because the default would silently decide the most important question about the result:
An out-of-bounds read in a C library is a fine envelope test and an impossible detection test. Recording "not found" against it as a miss is the easiest way to make a measurement lie.
Verification
ousast repos does not trust a recipe. Against a materialised checkout it checks that HEAD is the pinned
commit, that the licence file is really there, and that each declared function appears above its declared
line in its declared file. A recipe that contradicts the code exits non-zero; a recipe that simply has not
been fetched does not, or CI could never run this command.
That check 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.
What is pinned
| repo | language | size | measures | why |
|---|---|---|---|---|
vampi |
python | 520 lines, 11 files | detection | Small enough that a detection result is not confounded by budget or ranking. Its routes are registered through an OpenAPI operationId rather than decorators, so it exercises registration-based entry-point mapping. Excerpts of it are already in the pair corpus, so a whole-repository run says directly whether a verdict survives the move off the excerpt. |
libpng |
c | 91k lines, 101 files | envelope | Whether one CPG over a real C library is affordable at all: build time, query time, peak memory, and whether the ranker yields a sane number of regions. Its CVE is out of scope by construction. |
pmpro |
php | 117k lines, 637 files | detection, envelope | Paid Memberships Pro 2.9.7. CVE-2023-23488 is an unauthenticated SQL injection whose value reaches the sink inside the function that receives it -- the shape the PHP fact tables were built for. 2.9.8 wraps it in $wpdb->prepare, so the pair separates. |
mwwpform |
php | MW WP Form 5.0.3 | detection | CVE-2023-6559, an arbitrary file deletion. The fix adds realpath(), is_file() and a directory-confinement test, all of which the facts already carry, so this is a pair the engine can separate rather than merely flag. |
wpstatistics |
php | WP Statistics 13.1.x | detection | CVE-2022-25148, an unauthenticated SQL injection that crosses add_filter/apply_filters. Pinned because it is NOT expected to be found: a table of hits teaches nothing about where the engine stops. |
WordPress, class by class
WordPress's recurring flaw classes are narrow and well documented, which makes them a fair test: each one maps to a family this engine already has, so "not found" has to name a mechanism rather than shrug. Three plugins, each pinned at a version whose advisory was read out of the code and not out of the advisory text, and each measured against its own fixed commit.
| class | plugin, CVE | vulnerable side | fixed side | verdict |
|---|---|---|---|---|
| Unauthenticated injection, sink in the function that receives the value | pmpro, CVE-2023-23488 |
entailed at class.memberorder.php:936:getMemberOrderByCode, sourced from $code |
absent | found, and the pair separates |
| Arbitrary file operation | mwwpform, CVE-2023-6559 |
entailed at class.mail.php:259:_delete_files |
absent | found, and the pair separates |
| Unauthenticated injection, value crosses a WordPress hook | wpstatistics, CVE-2022-25148 |
entailed at class-wp-statistics-pages.php:225:record |
absent | found, and the pair separates |
| Missing capability check | — | — | — | cannot be asked: PHP has no obligation facts |
| Unescaped output | — | — | — | cannot be trusted: the sanitizer list is flat |
The two it finds
Both are entailed by the graph alone — no judge, no model call, no spend — and both disappear on the fixed
side because the fix is a call the fact tables already carry: $wpdb->prepare for one, realpath() for the
other. That is the distinction worth teaching. The engine is not recognising a bug; it is failing to find a
cleansing call on a path it resolved, and then finding one.
Every finding now names the value it followed. On PMPro's order class the vulnerable side reports 18
entailed findings and the fixed side 1, and each one is sourced either from a named parameter ($id,
$code, $token) or from a named field ($this->sqlQuery, $this->Email). None is sourced from $this.
That took two changes, and the order between them is the whole point. Excluding the receiver from parameter
sources was tried first and reverted: it cuts the file to 6 findings and makes the pair separate cleanly,
and it loses CVE-2023-6559, because _delete_files() takes no parameters at all and its
attacker-controlled path arrives as $this->attachments, assigned by another method entirely. Trading a
verified CVE for findings merely suspected of being false is the wrong trade.
With the field half of the join in place (below), that path is carried by the field it actually travels through, and the receiver no longer has to stand in for it — so it can go, and the eleven receiver-sourced findings go with it. The precision fix became available once the mechanism underneath it was right.
The one it misses, and why
WP Statistics' CVE is an unauthenticated REST hit whose current_page_id is interpolated into
$wpdb->get_row. Every piece is in scope — a modelled source, a modelled sink, and esc_sql as the fix —
and the engine still reports nothing, on both sides. The reason is checkable rather than inferred:
-
the file holding the sink contains zero superglobals;
-
it makes no call into the class holding the source;
-
the only connection between them is
add_filter('wp_statistics_current_page', array($this, 'set_current_page')); // hits.php:43 return apply_filters('wp_statistics_current_page', $current_page); // pages.php:105
Both ends name the callback with a string. No frontend can draw that edge, so no dataflow engine can cross it, and the honest description is not "we missed it" but "the graph does not contain the path". Most plugin data travels this way. It is the single largest structural gap for PHP, and it is not a fact-table problem.
It is also not a permanent one, and "structurally impossible" would be the wrong thing to leave here. Note
what is and is not missing: $_REQUEST reaching set_current_page's return is a path the graph has, and
apply_filters' return reaching $wpdb->get_row is a path the graph has. Only the join between them is
absent — and the key it joins on, 'wp_statistics_current_page', is a string literal written at both ends.
The same is true of $this->attachments in MW WP Form, where the key is a field name.
So the strategy is two-stage taint with a link table: ask the existing query for each half against a synthetic endpoint, build the table by reading literals rather than inferring anything, and join. The rung carries the join's uncertainty — one registered callback and a literal key entails, several callbacks or a computed hook name corroborates. Task 5.11 states it, with both pinned pairs as its observable.
The field half is implemented and measured. $this->attachments is tainted at the assignment that fills
it, joined to the read by the literal field code, so CVE-2023-6559 is found as
class.mail.php:259:_delete_files ← $this->attachments and is absent on the fixed side. One thing it needed
that is easy to get wrong: the summary has to carry the sanitization status of the half it summarises,
not merely its reachability. Asking only "does a source reach this assignment" marks
$this->sqlQuery = "..." . esc_sql($x) . "..." tainted, and PMPro builds most of its queries that way — the
fixed side went from 1 finding to 13 before that clause existed, which is the pair no longer separating at
all. It costs about 1.6× on the taint query for that class (62s → 97s), memoised per field.
The hook half is implemented too, and CVE-2022-25148 is found: class-wp-statistics-pages.php:225:record
on the vulnerable side, absent on the fixed side, with the correctly-prepared sibling query one line below
it not flagged on either. The link table is read from the source text, because php2cpg drops a registration's
callback argument entirely -- the CPG holds add_filter("wp_statistics_current_page", ), so the edge cannot
come from the graph at any price.
The half that mattered was asking per ARRAY KEY rather than per callback. "Does an unsanitized value reach
this callback's return" is true on both sides, because the fix escapes type and id and leaves
search_query alone; a callback-level answer flags the fix as readily as the bug. The key is a literal at
both ends — "id" where the callback writes it, ['id'] where the sink reads it — so it joins the same way
the hook name and the field name do. That is the same idea for the third time.
What the engine reports on that plugin instead is two other sites — getTop:406 and TotalCount:443 — the
same weakness class at the wrong lines, identical on both sides, so the pair does not separate. They are not
noise: upstream now annotates both with // phpcs:ignore WordPress.DB.PreparedSQL..., and later rewrote
one of them with $wpdb->prepare. Right class, wrong sites, no discrimination.
The two it cannot ask
dominance_specs(language="php") returns an empty mapping. There are no PHP obligation facts, so the
missing-capability class — current_user_can, check_admin_referer — is never asked, on any plugin, and
would report nothing however many were added. That is not a miss; nothing was measured. Recorded as 5.9.
output_encoding for PHP has sinks (echo, print, printf) and shares the one flat sanitizer list
with every other family. That list contains esc_sql, intval, realpath and escapeshellarg, none of
which escape HTML, and excludes esc_html and esc_attr, which are the only ones that do. So it is wrong in
both directions at once: it would accept echo esc_sql($x) as safe and report
echo esc_attr(sanitize_text_field($_REQUEST['login'])) — the pattern WordPress documents as correct, and
which appears verbatim at pmpro/includes/login.php:684 — as a finding. Until a sanitizer can say which
weakness class it cleanses, no XSS verdict from this engine means anything. Recorded as 5.6.
What nearly invalidated all of it
The first PMPro measurement in this series reported 64 regions examined, zero findings and zero degradations. The graph it examined had no methods in it.
php2cpg 4.0.623 reads its PHP parser's stdout and stderr as one merged stream, and the parser writes a
progress banner to stderr the moment it starts the next file — while the previous file's multi-megabyte JSON
is still draining from a block-buffered stdout. The banner lands inside the JSON, the file is dropped, and
joern-parse propagates none of it: thirteen lines of output, exit status 0, "Successfully wrote graph".
One oversized file empties the entire graph, so this was never the scale limit it looked like.
It is also a race, not a threshold. Five builds of the same two-file input: three produced a graph, two came back empty. Before the batched query started carrying a census of the graph, two of every five scans of that plugin would have reported a clean bill of health.
That is the argument for why a corpus of benchmarks is not enough on its own, made concretely. Every gate stayed byte-identical through all of it. A corpus tells you a verdict is right; it cannot tell you the verdict was reached by looking at anything.
Baselines
Task 6.1 turns a scan of a pinned checkout into a committed baseline, so a change to the fact tables or the queries can be read as findings gained, findings lost and rung movements (Req 10.1–10.4). Until then these recipes exist to be measured against by hand, and the first such measurement is task 2.2.