CVE-2017-14064 (published 2017-08-31T17:29Z)

Ruby through 2.2.7, 2.3.x through 2.3.4, and 2.4.x through 2.4.1 can expose arbitrary memory during a JSON.generate call. The issues lies in using strdup in ext/json/ext/generator/generator.c, which will stop after encountering a '\\0' byte, returning a pointer to a string of length zero, which is not the length stored in space_len.

Severity: HIGH
CVSS v2 base score: 7.5 (AV:N/AC:L/Au:N/C:P/I:P/A:P)
CVSS v3 base score: 9.8, CRITICAL (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

Weakness information:
cwe_id: CWE-119
cwe_name: Improper Restriction of Operations within the Bounds of a Memory Buffer
description: The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
extended_description: 
            Certain languages allow direct addressing of memory locations and do not automatically ensure that these locations are valid for the memory buffer that is being referenced. This can cause read or write operations to be performed on memory locations that may be associated with other variables, data structures, or internal program data.
         
         

Fix information:
repo_url: https://github.com/flori/json
commit_details: repo_url: https://github.com/flori/json
author: Florian Frank
author_date: 2017-03-02 12:12:33+01:00
msg: Fix arbitrary heap exposure problem
repository: repo_url: https://github.com/flori/json
repo_name: flori/json
description: JSON implementation for Ruby
repo_language: Ruby
owner: flori
file_changes: filename: generator.c
change_type: ModificationType.MODIFY
diff: @@ -308,7 +308,7 @@ static char *fstrndup(const char *ptr, unsigned long len) {
   char *result;
   if (len <= 0) return NULL;
   result = ALLOC_N(char, len);
-  memccpy(result, ptr, 0, len);
+  memcpy(result, ptr, len);
   return result;
 }
 
@@ -1062,7 +1062,7 @@ static VALUE cState_indent_set(VALUE self, VALUE indent)
         }
     } else {
         if (state->indent) ruby_xfree(state->indent);
-        state->indent = strdup(RSTRING_PTR(indent));
+        state->indent = fstrndup(RSTRING_PTR(indent), len);
         state->indent_len = len;
     }
     return Qnil;
@@ -1100,7 +1100,7 @@ static VALUE cState_space_set(VALUE self, VALUE space)
         }
     } else {
         if (state->space) ruby_xfree(state->space);
-        state->space = strdup(RSTRING_PTR(space));
+        state->space = fstrndup(RSTRING_PTR(space), len);
         state->space_len = len;
     }
     return Qnil;
@@ -1136,7 +1136,7 @@ static VALUE cState_space_before_set(VALUE self, VALUE space_before)
         }
     } else {
         if (state->space_before) ruby_xfree(state->space_before);
-        state->space_before = strdup(RSTRING_PTR(space_before));
+        state->space_before = fstrndup(RSTRING_PTR(space_before), len);
         state->space_before_len = len;
     }
     return Qnil;
@@ -1173,7 +1173,7 @@ static VALUE cState_object_nl_set(VALUE self, VALUE object_nl)
         }
     } else {
         if (state->object_nl) ruby_xfree(state->object_nl);
-        state->object_nl = strdup(RSTRING_PTR(object_nl));
+        state->object_nl = fstrndup(RSTRING_PTR(object_nl), len);
         state->object_nl_len = len;
     }
     return Qnil;
@@ -1208,7 +1208,7 @@ static VALUE cState_array_nl_set(VALUE self, VALUE array_nl)
         }
     } else {
         if (state->array_nl) ruby_xfree(state->array_nl);
-        state->array_nl = strdup(RSTRING_PTR(array_nl));
+        state->array_nl = fstrndup(RSTRING_PTR(array_nl), len);
         state->array_nl_len = len;
     }
     return Qnil;

programming_language: C
filename: generator.h
change_type: ModificationType.MODIFY
diff: @@ -1,7 +1,6 @@
 #ifndef _GENERATOR_H_
 #define _GENERATOR_H_
 
-#include <string.h>
 #include <math.h>
 #include <ctype.h>
 

programming_language: SQL