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From 427120b41a141626dbb40a752c848f199fc9f7a8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stefan=20B=C3=BChler?= <stbuehler@web.de>
Date: Thu, 28 May 2015 15:47:14 +0000
Subject: [PATCH 29/29] =?UTF-8?q?escape=20all=20strings=20for=20logging=20?=
=?UTF-8?q?(fixes=20#2646=20log=20file=20injection,=20reported=20by=20Jaan?=
=?UTF-8?q?us=20K=C3=A4=C3=A4p)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
From: Stefan Bühler <stbuehler@web.de>
git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-1.4.x@2989 152afb58-edef-0310-8abb-c4023f1b3aa9
---
NEWS | 5 +++--
src/buffer.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
src/buffer.h | 5 ++++-
src/log.c | 8 ++++----
4 files changed, 70 insertions(+), 7 deletions(-)
diff --git a/NEWS b/NEWS
index dd2d1b8..18007fc 100644
--- a/NEWS
+++ b/NEWS
@@ -19,6 +19,7 @@ NEWS
* [mod_auth] use crypt_r instead of crypt if available
* fix error message for T_CONFIG_ARRAY config values if an entry value is not a string
* fix segfaults in many plugins if they failed configuration
+ * escape all strings for logging (fixes #2646 log file injection, reported by Jaanus Kääp)
- 1.4.35 - 2014-03-12
* [network/ssl] fix build error if TLSEXT is disabled
@@ -557,10 +558,10 @@ NEWS
* ignore empty packets from STDERR stream. #998
* fix a crash for files with an mtime of 0 reported by cubiq on irc [1519]
CVE-2007-1870
- * allow empty passwords with ldap (Jörg Sonnenberger) [1516]
+ * allow empty passwords with ldap (Jörg Sonnenberger) [1516]
* mod_scgi.c segfault fix #964 [1501]
* Added round-robin support to mod_fastcgi [1500]
- * Handle DragonFlyBSD the same way as Freebsd (Jörg Sonnenberger) [1492,1676]
+ * Handle DragonFlyBSD the same way as Freebsd (Jörg Sonnenberger) [1492,1676]
* added now and weeks support to mod_expire. #943
* fix cpu hog in certain requests [1473] CVE-2007-1869
* fix for handling hostnames with trailing dot [1406]
diff --git a/src/buffer.c b/src/buffer.c
index 57c1613..36995a0 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -731,6 +731,65 @@ void buffer_append_string_encoded(buffer *b, const char *s, size_t s_len, buffer
}
}
+void buffer_append_string_c_escaped(buffer *b, const char *s, size_t s_len) {
+ unsigned char *ds, *d;
+ size_t d_len, ndx;
+
+ force_assert(NULL != b);
+ force_assert(NULL != s || 0 == s_len);
+
+ if (0 == s_len) return;
+
+ /* count to-be-encoded-characters */
+ for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
+ if ((*ds < 0x20) /* control character */
+ || (*ds >= 0x7f)) { /* DEL + non-ASCII characters */
+ switch (*ds) {
+ case '\t':
+ case '\r':
+ case '\n':
+ d_len += 2;
+ break;
+ default:
+ d_len += 4; /* \xCC */
+ break;
+ }
+ } else {
+ d_len++;
+ }
+ }
+
+ d = (unsigned char*) buffer_string_prepare_append(b, d_len);
+ buffer_commit(b, d_len); /* fill below */
+ force_assert('\0' == *d);
+
+ for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
+ if ((*ds < 0x20) /* control character */
+ || (*ds >= 0x7f)) { /* DEL + non-ASCII characters */
+ d[d_len++] = '\\';
+ switch (*ds) {
+ case '\t':
+ d[d_len++] = 't';
+ break;
+ case '\r':
+ d[d_len++] = 'r';
+ break;
+ case '\n':
+ d[d_len++] = 'n';
+ break;
+ default:
+ d[d_len++] = 'x';
+ d[d_len++] = hex_chars[((*ds) >> 4) & 0x0F];
+ d[d_len++] = hex_chars[(*ds) & 0x0F];
+ break;
+ }
+ } else {
+ d[d_len++] = *ds;
+ }
+ }
+}
+
+
void buffer_copy_string_encoded_cgi_varnames(buffer *b, const char *s, size_t s_len, int is_http_header) {
size_t i, j;
diff --git a/src/buffer.h b/src/buffer.h
index b6065d4..5f659df 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -133,6 +133,9 @@ typedef enum {
void buffer_append_string_encoded(buffer *b, const char *s, size_t s_len, buffer_encoding_t encoding);
+/* escape non-printable characters; simple escapes for \t, \r, \n; fallback to \xCC */
+void buffer_append_string_c_escaped(buffer *b, const char *s, size_t s_len);
+
/* to upper case, replace non alpha-numerics with '_'; if is_http_header prefix with "HTTP_" unless s is "content-type" */
void buffer_copy_string_encoded_cgi_varnames(buffer *b, const char *s, size_t s_len, int is_http_header);
@@ -164,7 +167,7 @@ static inline void buffer_append_slash(buffer *b); /* append '/' no non-empty st
buffer_copy_string_len(x, y, sizeof(y) - 1)
#define CONST_STR_LEN(x) x, (x) ? sizeof(x) - 1 : 0
-#define CONST_BUF_LEN(x) (x)->ptr, buffer_string_length(x)
+#define CONST_BUF_LEN(x) ((x) ? (x)->ptr : NULL), buffer_string_length(x)
#define UNUSED(x) ( (void)(x) )
diff --git a/src/log.c b/src/log.c
index 9322d2c..94f4710 100644
--- a/src/log.c
+++ b/src/log.c
@@ -267,12 +267,12 @@ static void log_buffer_append_printf(buffer *out, const char *fmt, va_list ap) {
switch(*fmt) {
case 's': /* string */
s = va_arg(ap, char *);
- buffer_append_string(out, s);
+ buffer_append_string_c_escaped(out, s, (NULL != s) ? strlen(s) : 0);
buffer_append_string_len(out, CONST_STR_LEN(" "));
break;
case 'b': /* buffer */
b = va_arg(ap, buffer *);
- buffer_append_string_buffer(out, b);
+ buffer_append_string_c_escaped(out, CONST_BUF_LEN(b));
buffer_append_string_len(out, CONST_STR_LEN(" "));
break;
case 'd': /* int */
@@ -293,11 +293,11 @@ static void log_buffer_append_printf(buffer *out, const char *fmt, va_list ap) {
break;
case 'S': /* string */
s = va_arg(ap, char *);
- buffer_append_string(out, s);
+ buffer_append_string_c_escaped(out, s, (NULL != s) ? strlen(s) : 0);
break;
case 'B': /* buffer */
b = va_arg(ap, buffer *);
- buffer_append_string_buffer(out, b);
+ buffer_append_string_c_escaped(out, CONST_BUF_LEN(b));
break;
case 'D': /* int */
d = va_arg(ap, int);
--
2.4.5
|
