File apache2-CVE-2024-38475-3.patch of Package apache2.35276
Index: httpd-2.4.58/modules/mappers/mod_rewrite.c
===================================================================
--- httpd-2.4.58.orig/modules/mappers/mod_rewrite.c
+++ httpd-2.4.58/modules/mappers/mod_rewrite.c
@@ -177,6 +177,8 @@ static const char* really_last_key = "re
#define RULEFLAG_QSLAST (1<<19)
#define RULEFLAG_QSNONE (1<<20) /* programattic only */
#define RULEFLAG_ESCAPECTLS (1<<21)
+#define RULEFLAG_UNSAFE_PREFIX_STAT (1<<22)
+#define RULEFLAG_UNSAFE_ALLOW3F (1<<23)
/* return code of the rewrite rule
* the result may be escaped - or not
@@ -184,7 +186,7 @@ static const char* really_last_key = "re
#define ACTION_NORMAL (1<<0)
#define ACTION_NOESCAPE (1<<1)
#define ACTION_STATUS (1<<2)
-
+#define ACTION_STATUS_SET (1<<3)
#define MAPTYPE_TXT (1<<0)
#define MAPTYPE_DBM (1<<1)
@@ -208,6 +210,7 @@ static const char* really_last_key = "re
#define OPTION_IGNORE_INHERIT (1<<8)
#define OPTION_IGNORE_CONTEXT_INFO (1<<9)
#define OPTION_LEGACY_PREFIX_DOCROOT (1<<10)
+#define OPTION_UNSAFE_PREFIX_STAT (1<<12)
#ifndef RAND_MAX
#define RAND_MAX 32767
@@ -301,6 +304,14 @@ typedef enum {
CONDPAT_AP_EXPR
} pattern_type;
+typedef enum {
+ RULE_RC_NOMATCH = 0, /* the rule didn't match */
+ RULE_RC_MATCH = 1, /* a matching rule w/ substitution */
+ RULE_RC_NOSUB = 2, /* a matching rule w/ no substitution */
+ RULE_RC_STATUS_SET = 3 /* a matching rule that has set an HTTP error
+ to be returned in r->status */
+} rule_return_type;
+
typedef struct {
char *input; /* Input string of RewriteCond */
char *pattern; /* the RegExp pattern string */
@@ -927,10 +938,15 @@ static void fully_qualify_uri(request_re
return;
}
+static int startsWith(request_rec *r, const char *haystack, const char *needle) {
+ int rc = (ap_strstr_c(haystack, needle) == haystack);
+ rewritelog((r, 5, NULL, "prefix_stat startsWith(%s, %s) %d", haystack, needle, rc));
+ return rc;
+}
/*
- * stat() only the first segment of a path
+ * stat() only the first segment of a path, and only if it matches the output of the last matching rule
*/
-static int prefix_stat(const char *path, apr_pool_t *pool)
+static int prefix_stat(request_rec *r, const char *path, apr_pool_t *pool, rewriterule_entry *lastsub)
{
const char *curpath = path;
const char *root;
@@ -964,10 +980,36 @@ static int prefix_stat(const char *path,
apr_finfo_t sb;
if (apr_stat(&sb, statpath, APR_FINFO_MIN, pool) == APR_SUCCESS) {
- return 1;
+ if (!lastsub) {
+ rewritelog((r, 3, NULL, "prefix_stat no lastsub subst prefix %s", statpath));
+ return 1;
+ }
+
+ rewritelog((r, 3, NULL, "prefix_stat compare statpath %s and lastsub output %s STATOK %d ",
+ statpath, lastsub->output, lastsub->flags & RULEFLAG_UNSAFE_PREFIX_STAT));
+ if (lastsub->flags & RULEFLAG_UNSAFE_PREFIX_STAT) {
+ return 1;
+ }
+ else {
+ const char *docroot = ap_document_root(r);
+ const char *context_docroot = ap_context_document_root(r);
+ /*
+ * As an example, path (r->filename) is /var/foo/bar/baz.html
+ * even if the flag is not set, we can accept a rule that
+ * began with a literal /var (stapath), or if the entire path
+ * starts with the docroot or context document root
+ */
+ if (startsWith(r, lastsub->output, statpath) ||
+ startsWith(r, path, docroot) ||
+ ((docroot != context_docroot) &&
+ startsWith(r, path, context_docroot))) {
+ return 1;
+ }
+ }
}
}
+ /* prefix will be added */
return 0;
}
@@ -3072,6 +3114,9 @@ static const char *cmd_rewriteoptions(cm
else if (!strcasecmp(w, "legacyprefixdocroot")) {
options |= OPTION_LEGACY_PREFIX_DOCROOT;
}
+ else if (!strcasecmp(w, "UnsafePrefixStat")) {
+ options |= OPTION_UNSAFE_PREFIX_STAT;
+ }
else {
return apr_pstrcat(cmd->pool, "RewriteOptions: unknown option '",
w, "'", NULL);
@@ -3780,6 +3825,18 @@ static const char *cmd_rewriterule_setfl
++error;
}
break;
+ case 'u':
+ case 'U':
+ if (!strcasecmp(key, "nsafePrefixStat")){
+ cfg->flags |= (RULEFLAG_UNSAFE_PREFIX_STAT);
+ }
+ else if(!strcasecmp(key, "nsafeAllow3F")) {
+ cfg->flags |= RULEFLAG_UNSAFE_ALLOW3F;
+ }
+ else {
+ ++error;
+ }
+ break;
default:
++error;
break;
@@ -4138,7 +4195,8 @@ static APR_INLINE void force_type_handle
/*
* Apply a single RewriteRule
*/
-static int apply_rewrite_rule(rewriterule_entry *p, rewrite_ctx *ctx)
+static rule_return_type apply_rewrite_rule(rewriterule_entry *p,
+ rewrite_ctx *ctx)
{
ap_regmatch_t regmatch[AP_MAX_REG_MATCH];
apr_array_header_t *rewriteconds;
@@ -4189,7 +4247,7 @@ static int apply_rewrite_rule(rewriterul
rc = !ap_regexec(p->regexp, ctx->uri, AP_MAX_REG_MATCH, regmatch, 0);
if (! (( rc && !(p->flags & RULEFLAG_NOTMATCH)) ||
(!rc && (p->flags & RULEFLAG_NOTMATCH)) ) ) {
- return 0;
+ return RULE_RC_NOMATCH;
}
/* It matched, wow! Now it's time to prepare the context structure for
@@ -4240,7 +4298,7 @@ static int apply_rewrite_rule(rewriterul
}
}
else if (!rc) {
- return 0;
+ return RULE_RC_NOMATCH;
}
/* If some HTTP header was involved in the condition, remember it
@@ -4260,6 +4318,15 @@ static int apply_rewrite_rule(rewriterul
newuri = do_expand(p->output, ctx, p);
rewritelog((r, 2, ctx->perdir, "rewrite '%s' -> '%s'", ctx->uri,
newuri));
+ if (!(p->flags & RULEFLAG_UNSAFE_ALLOW3F) &&
+ ap_strcasestr(r->unparsed_uri, "%3f") &&
+ ap_strchr_c(newuri, '?')) {
+ ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO()
+ "Unsafe URL with %%3f URL rewritten without "
+ "UnsafeAllow3F");
+ r->status = HTTP_FORBIDDEN;
+ return RULE_RC_STATUS_SET;
+ }
}
/* expand [E=var:val] and [CO=<cookie>] */
@@ -4277,7 +4344,7 @@ static int apply_rewrite_rule(rewriterul
r->status = p->forced_responsecode;
}
- return 2;
+ return RULE_RC_NOSUB;
}
/* Add the previously stripped per-directory location prefix, unless
@@ -4343,7 +4410,7 @@ static int apply_rewrite_rule(rewriterul
r->filename));
r->filename = apr_pstrcat(r->pool, "proxy:", r->filename, NULL);
- return 1;
+ return RULE_RC_MATCH;
}
/* If this rule is explicitly forced for HTTP redirection
@@ -4358,7 +4425,7 @@ static int apply_rewrite_rule(rewriterul
r->filename));
r->status = p->forced_responsecode;
- return 1;
+ return RULE_RC_MATCH;
}
/* Special Rewriting Feature: Self-Reduction
@@ -4380,7 +4447,7 @@ static int apply_rewrite_rule(rewriterul
"with %s", p->forced_responsecode, r->filename));
r->status = p->forced_responsecode;
- return 1;
+ return RULE_RC_MATCH;
}
/* Finally remember the forced mime-type */
@@ -4389,7 +4456,7 @@ static int apply_rewrite_rule(rewriterul
/* Puuhhhhhhhh... WHAT COMPLICATED STUFF ;_)
* But now we're done for this particular rule.
*/
- return 1;
+ return RULE_RC_MATCH;
}
/*
@@ -4397,13 +4464,13 @@ static int apply_rewrite_rule(rewriterul
* i.e. a list of rewrite rules
*/
static int apply_rewrite_list(request_rec *r, apr_array_header_t *rewriterules,
- char *perdir)
+ char *perdir, rewriterule_entry **lastsub)
{
rewriterule_entry *entries;
rewriterule_entry *p;
int i;
int changed;
- int rc;
+ rule_return_type rc;
int s;
rewrite_ctx *ctx;
int round = 1;
@@ -4411,6 +4478,7 @@ static int apply_rewrite_list(request_re
ctx = apr_palloc(r->pool, sizeof(*ctx));
ctx->perdir = perdir;
ctx->r = r;
+ *lastsub = NULL;
/*
* Iterate over all existing rules
@@ -4438,7 +4506,12 @@ static int apply_rewrite_list(request_re
ctx->vary = NULL;
rc = apply_rewrite_rule(p, ctx);
- if (rc) {
+ if (rc != RULE_RC_NOMATCH) {
+
+ if (!(p->flags & RULEFLAG_NOSUB)) {
+ rewritelog((r, 2, perdir, "setting lastsub to rule with output %s", p->output));
+ *lastsub = p;
+ }
/* Catch looping rules with pathinfo growing unbounded */
if ( strlen( r->filename ) > 2*r->server->limit_req_line ) {
@@ -4458,6 +4531,12 @@ static int apply_rewrite_list(request_re
apr_table_merge(r->headers_out, "Vary", ctx->vary);
}
+
+ /* Error while evaluating rule, r->status set */
+ if (RULE_RC_STATUS_SET == rc) {
+ return ACTION_STATUS_SET;
+ }
+
/*
* The rule sets the response code (implies match-only)
*/
@@ -4468,7 +4547,7 @@ static int apply_rewrite_list(request_re
/*
* Indicate a change if this was not a match-only rule.
*/
- if (rc != 2) {
+ if (rc != RULE_RC_NOSUB) {
changed = ((p->flags & RULEFLAG_NOESCAPE)
? ACTION_NOESCAPE : ACTION_NORMAL);
}
@@ -4657,6 +4736,7 @@ static int hook_uri2file(request_rec *r)
int rulestatus;
void *skipdata;
const char *oargs;
+ rewriterule_entry *lastsub = NULL;
/*
* retrieve the config structures
@@ -4768,7 +4848,7 @@ static int hook_uri2file(request_rec *r)
/*
* now apply the rules ...
*/
- rulestatus = apply_rewrite_list(r, conf->rewriterules, NULL);
+ rulestatus = apply_rewrite_list(r, conf->rewriterules, NULL, &lastsub);
apr_table_setn(r->notes, "mod_rewrite_rewritten",
apr_psprintf(r->pool,"%d",rulestatus));
}
@@ -4806,6 +4886,9 @@ static int hook_uri2file(request_rec *r)
r->status = HTTP_OK;
return n;
}
+ else if (ACTION_STATUS_SET == rulestatus) {
+ return r->status;
+ }
if (to_proxyreq) {
/* it should be go on as an internal proxy request */
@@ -4925,23 +5008,29 @@ static int hook_uri2file(request_rec *r)
return HTTP_BAD_REQUEST;
}
- /* if there is no valid prefix, we call
- * the translator from the core and
- * prefix the filename with document_root
+ /* We have r->filename as a path in a server-context rewrite without
+ * the PT flag. The historical behavior is to treat it as a verbatim
+ * filesystem path iff the first component of the path exists and is
+ * readable by httpd. Otherwise, it is interpreted as DocumentRoot
+ * relative.
*
* NOTICE:
* We cannot leave out the prefix_stat because
- * - when we always prefix with document_root
- * then no absolute path can be created, e.g. via
- * emulating a ScriptAlias directive, etc.
- * - when we always NOT prefix with document_root
+ * - If we always prefix with document_root
+ * then no absolute path can could ever be used in
+ * a substitution. e.g. emulating an Alias.
+ * - If we never prefix with document_root
* then the files under document_root have to
* be references directly and document_root
* gets never used and will be a dummy parameter -
- * this is also bad
+ * this is also bad.
+ * - Later addition: This part is questionable.
+ * If we had never prefixed, users would just
+ * need %{DOCUMENT_ROOT} in substitutions or the
+ * [PT] flag.
*
* BUT:
- * Under real Unix systems this is no problem,
+ * Under real Unix systems this is no perf problem,
* because we only do stat() on the first directory
* and this gets cached by the kernel for along time!
*/
@@ -4950,7 +5039,9 @@ static int hook_uri2file(request_rec *r)
uri_reduced = apr_table_get(r->notes, "mod_rewrite_uri_reduced");
}
- if (!prefix_stat(r->filename, r->pool) || uri_reduced != NULL) {
+ if (!prefix_stat(r, r->filename, r->pool,
+ conf->options & OPTION_UNSAFE_PREFIX_STAT ? NULL : lastsub)
+ || uri_reduced != NULL) {
int res;
char *tmp = r->uri;
@@ -4995,6 +5086,7 @@ static int hook_fixup(request_rec *r)
char *ofilename, *oargs;
int is_proxyreq;
void *skipdata;
+ rewriterule_entry *lastsub;
dconf = (rewrite_perdir_conf *)ap_get_module_config(r->per_dir_config,
&rewrite_module);
@@ -5079,7 +5171,7 @@ static int hook_fixup(request_rec *r)
/*
* now apply the rules ...
*/
- rulestatus = apply_rewrite_list(r, dconf->rewriterules, dconf->directory);
+ rulestatus = apply_rewrite_list(r, dconf->rewriterules, dconf->directory, &lastsub);
if (rulestatus) {
unsigned skip_absolute = is_absolute_uri(r->filename, NULL);
int to_proxyreq = 0;
@@ -5108,6 +5200,9 @@ static int hook_fixup(request_rec *r)
r->status = HTTP_OK;
return n;
}
+ else if (ACTION_STATUS_SET == rulestatus) {
+ return r->status;
+ }
if (to_proxyreq) {
/* it should go on as an internal proxy request */
