File SQUID-2020_10.patch of Package squid.31747
from
commit 9c8e2a71aa1d3c159a319d9365c346c48dc783a5
Author: Amos Jeffries <yadij@users.noreply.github.com>
Date: Tue Aug 4 04:34:32 2020 +0000
Enforce token characters for field-name (#700)
RFC 7230 defines field-name as a token. Request splitting and cache
poisoning attacks have used non-token characters to fool broken HTTP
agents behind or in front of Squid for years. This change should
significantly reduce that abuse.
If we discover exceptional situations that need special treatment, the
relaxed parser can allow them on a case-by-case basis (while being extra
careful about framing-related header fields), just like we already
tolerate some header whitespace (e.g., between the response header
field-name and colon).
Index: squid-3.5.21/src/HttpHeader.cc
===================================================================
--- squid-3.5.21.orig/src/HttpHeader.cc
+++ squid-3.5.21/src/HttpHeader.cc
@@ -29,6 +29,7 @@
#include "StrList.h"
#include "TimeOrTag.h"
#include "http/ContentLengthInterpreter.h"
+#include "base/CharacterSet.h"
#include <algorithm>
@@ -705,17 +706,6 @@ HttpHeader::parse(const char *header_sta
return 0;
}
- if (e->id == HDR_OTHER && stringHasWhitespace(e->name.termedBuf())) {
- debugs(55, warnOnError, "WARNING: found whitespace in HTTP header name {" <<
- getStringPrefix(field_start, field_end) << "}");
-
- if (!Config.onoff.relaxed_header_parser) {
- delete e;
- PROF_stop(HttpHeaderParse);
- return reset();
- }
- }
-
addEntry(e);
}
@@ -1679,6 +1669,21 @@ HttpHeaderEntry::parse(const char *field
}
}
+ /* RFC 7230 section 3.2:
+ *
+ * header-field = field-name ":" OWS field-value OWS
+ * field-name = token
+ * token = 1*TCHAR
+ */
+ for (const char *pos = field_start; pos < (field_start+name_len); ++pos) {
+ if (!CharacterSet::TCHAR[*pos]) {
+ debugs(55, 2, "found header with invalid characters in " <<
+ Raw("field-name", field_start, min(name_len,100)) << "...");
+ return nullptr;
+ }
+ }
+
+
/* now we know we can parse it */
debugs(55, 9, "parsing HttpHeaderEntry: near '" << getStringPrefix(field_start, field_end) << "'");