Fix check_snmp buffer overflow (CVE-2007-5623)

This patch comes from the Gentoo Portage tree but I couldn't find the author. I sent an email and will give credits when I get an answer.


git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@1814 f882894a-f735-0410-b71e-b25c423dba1c

1 files changed, 10 insertions, 6 deletions

diff --git a/plugins/check_snmp.c b/plugins/check_snmp.c
index 3f9a03d..9fa4a60 100644
--- a/plugins/check_snmp.c
+++ b/plugins/check_snmp.c
@@ -226,12 +226,16 @@ main (int argc, char **argv)
 
         ptr = output;
 
-        strcat(perfstr, "| ");
+        strncat(perfstr, "| ", sizeof(perfstr)-strlen(perfstr)-1);
         while (ptr) {
                 char *foo;
+                unsigned int copylen;
 
                 foo = strstr (ptr, delimiter);
-                strncat(perfstr, ptr, foo-ptr);
+                copylen = foo-ptr;
+                if (copylen > sizeof(perfstr)-strlen(perfstr)-1)
+                        copylen = sizeof(perfstr)-strlen(perfstr)-1;
+                strncat(perfstr, ptr, copylen);
                 ptr = foo; 
 
                 if (ptr == NULL)
@@ -364,11 +368,11 @@ main (int argc, char **argv)
 
                 i++;
 
-                strcat(perfstr, "=");
-                strcat(perfstr, show);
+                strncat(perfstr, "=", sizeof(perfstr)-strlen(perfstr)-1);
+                strncat(perfstr, show, sizeof(perfstr)-strlen(perfstr)-1);
                 if (type)
-                        strcat(perfstr, type);
-                strcat(perfstr, " ");
+                        strncat(perfstr, type, sizeof(perfstr)-strlen(perfstr)-1);
+                strncat(perfstr, " ", sizeof(perfstr)-strlen(perfstr)-1);
 
         }       /* end while (ptr) */