diff --git a/ChangeLog b/ChangeLog
index fc06c9b16f..4a42940905 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+Sat May 21 05:43:03 2011  URABE Shyouhei  <shyouhei@ruby-lang.org>
+
+	* eval.c (rb_thread_atfork): When a ruby process forks, its random
+	  seed shall be reinitialized to prevent CVE-2003-0900 situation.
+	  This bug affects for 1.8 and earlier series, but not for 1.9.
+	  fixed [ruby-core:34944].
+
+	* io.c (pipe_open): ditto.
+
+	* random.c (rb_reset_random_seed): ditto.
+
+	* intern.h (rb_reset_random_seed): ditto.
+
 Sat May 21 04:55:15 2011  Akinori MUSHA  <knu@iDaemons.org>
 
 	* lib/uri/generic.rb (#route_from_path): Fix a bug where
diff --git a/eval.c b/eval.c
index 284e48666f..7886e17d1a 100644
--- a/eval.c
+++ b/eval.c
@@ -13178,6 +13178,7 @@ rb_thread_atfork()
 {
     rb_thread_t th;
 
+    rb_reset_random_seed();
     if (rb_thread_alone()) return;
     FOREACH_THREAD(th) {
 	if (th != curr_thread) {
diff --git a/intern.h b/intern.h
index acae58db45..950ae9dad0 100644
--- a/intern.h
+++ b/intern.h
@@ -380,6 +380,7 @@ VALUE rb_length_by_each _((VALUE));
 /* random.c */
 unsigned long rb_genrand_int32(void);
 double rb_genrand_real(void);
+void rb_reset_random_seed(void);
 /* re.c */
 int rb_memcmp _((const void*,const void*,long));
 int rb_memcicmp _((const void*,const void*,long));
diff --git a/io.c b/io.c
index 6f420b16ac..00a1820d88 100644
--- a/io.c
+++ b/io.c
@@ -3254,6 +3254,7 @@ retry:
     rb_thread_stop_timer();
     switch ((pid = fork())) {
       case 0:			/* child */
+        rb_thread_atfork();
 	if (modef & FMODE_READABLE) {
 	    close(pr[0]);
 	    if (pr[1] != 1) {
diff --git a/random.c b/random.c
index 258b0b2230..c0560e3573 100644
--- a/random.c
+++ b/random.c
@@ -491,9 +491,15 @@ rb_f_rand(argc, argv, obj)
 }
 
 void
-Init_Random()
+rb_reset_random_seed()
 {
     rand_init(random_seed());
+}
+
+void
+Init_Random()
+{
+    rb_reset_random_seed();
     rb_define_global_function("srand", rb_f_srand, -1);
     rb_define_global_function("rand", rb_f_rand, -1);
     rb_global_variable(&saved_seed);
diff --git a/version.h b/version.h
index 4d3f1e25c9..ef23dc525f 100644
--- a/version.h
+++ b/version.h
@@ -1,15 +1,15 @@
 #define RUBY_VERSION "1.8.7"
-#define RUBY_RELEASE_DATE "2011-05-21"
+#define RUBY_RELEASE_DATE "2011-05-23"
 #define RUBY_VERSION_CODE 187
-#define RUBY_RELEASE_CODE 20110521
-#define RUBY_PATCHLEVEL 344
+#define RUBY_RELEASE_CODE 20110523
+#define RUBY_PATCHLEVEL 345
 
 #define RUBY_VERSION_MAJOR 1
 #define RUBY_VERSION_MINOR 8
 #define RUBY_VERSION_TEENY 7
 #define RUBY_RELEASE_YEAR 2011
 #define RUBY_RELEASE_MONTH 5
-#define RUBY_RELEASE_DAY 21
+#define RUBY_RELEASE_DAY 23
 
 #ifdef RUBY_EXTERN
 RUBY_EXTERN const char ruby_version[];