Fix bug #7669.

Fix bug #7669 (buffer overflow in sid_parse() in Samba3 and dom_sid_parse in
Samba4).

CVE-2010-3069:

===========
Description
===========

All current released versions of Samba are vulnerable to
a buffer overrun vulnerability. The sid_parse() function
(and related dom_sid_parse() function in the source4 code)
do not correctly check their input lengths when reading a
binary representation of a Windows SID (Security ID). This
allows a malicious client to send a sid that can overflow
the stack variable that is being used to store the SID in the
Samba smbd server.

A connection to a file share is needed to exploit this
vulnerability, either authenticated or unauthenticated
(guest connection).

diff --git a/source/lib/util_sid.c b/source/lib/util_sid.c
index f656bb13dc8807c582e4471c54ef755a60076cd3..aa49b860d039f066b5281d8cf9ae4dd49a2b9ab1 100644 (file)
--- a/source/lib/util_sid.c
+++ b/source/lib/util_sid.c
@@ -408,6 +408,9 @@ bool sid_parse(const char *inbuf, size_t len, DOM_SID *sid)
 
        sid->sid_rev_num = CVAL(inbuf, 0);
        sid->num_auths = CVAL(inbuf, 1);
+       if (sid->num_auths > MAXSUBAUTHS) {
+               return false;
+       }
        memcpy(sid->id_auth, inbuf+2, 6);
        if (len < 8 + sid->num_auths*4)
                return False;

diff --git a/source/libads/ldap.c b/source/libads/ldap.c
index d9598e5dd8308ce4edca71027fd33bf7447c5576..f426996968fbbbfdb388f848404fa6427773c722 100644 (file)
--- a/source/libads/ldap.c
+++ b/source/libads/ldap.c
@@ -2139,7 +2139,9 @@ static void dump_sid(ADS_STRUCT *ads, const char *field, struct berval **values)
        for (i=0; values[i]; i++) {
                DOM_SID sid;
                fstring tmp;
-               sid_parse(values[i]->bv_val, values[i]->bv_len, &sid);
+               if (!sid_parse(values[i]->bv_val, values[i]->bv_len, &sid)) {
+                       continue;
+               }
                printf("%s: %s\n", field, sid_to_fstring(tmp, &sid));
        }
 }

diff --git a/source/libsmb/cliquota.c b/source/libsmb/cliquota.c
index dcdfec241d915b5694895fe5a5f5775d395ecbbd..47739f04a07d598e15ab5606f00adbbd5fba61d0 100644 (file)
--- a/source/libsmb/cliquota.c
+++ b/source/libsmb/cliquota.c
@@ -117,7 +117,9 @@ static bool parse_user_quota_record(const char *rdata, unsigned int rdata_count,
        }
 #endif /* LARGE_SMB_OFF_T */
 
-       sid_parse(rdata+40,sid_len,&qt.sid);
+       if (!sid_parse(rdata+40,sid_len,&qt.sid)) {
+               return false;
+       }
 
        qt.qtype = SMB_USER_QUOTA_TYPE;
 

diff --git a/source/smbd/nttrans.c b/source/smbd/nttrans.c
index c392380b5ec7e39adff73fe2a2c8b991c71dc464..b610b1fd397859bd978d80a72a049fe4cad20822 100644 (file)
--- a/source/smbd/nttrans.c
+++ b/source/smbd/nttrans.c
@@ -1950,7 +1950,11 @@ static void call_nt_transact_ioctl(connection_struct *conn,
                /* unknown 4 bytes: this is not the length of the sid :-(  */
                /*unknown = IVAL(pdata,0);*/
 
-               sid_parse(pdata+4,sid_len,&sid);
+               if (!sid_parse(pdata+4,sid_len,&sid)) {
+                       reply_nterror(req, NT_STATUS_INVALID_PARAMETER);
+                       return;
+               }
+
                DEBUGADD(10, ("for SID: %s\n", sid_string_dbg(&sid)));
 
                if (!sid_to_uid(&sid, &uid)) {
@@ -2206,7 +2210,10 @@ static void call_nt_transact_get_user_quota(connection_struct *conn,
                                break;
                        }
 
-                       sid_parse(pdata+8,sid_len,&sid);
+                       if (!sid_parse(pdata+8,sid_len,&sid)) {
+                               reply_nterror(req, NT_STATUS_INVALID_PARAMETER);
+                               return;
+                       }
 
                        if (vfs_get_ntquota(fsp, SMB_USER_QUOTA_TYPE, &sid, &qt)!=0) {
                                ZERO_STRUCT(qt);
@@ -2387,7 +2394,11 @@ static void call_nt_transact_set_user_quota(connection_struct *conn,
        }
 #endif /* LARGE_SMB_OFF_T */
 
-       sid_parse(pdata+40,sid_len,&sid);
+       if (!sid_parse(pdata+40,sid_len,&sid)) {
+               reply_nterror(req, NT_STATUS_INVALID_PARAMETER);
+               return;
+       }
+
        DEBUGADD(8,("SID: %s\n", sid_string_dbg(&sid)));
 
        /* 44 unknown bytes left... */