freebsd-ports/security/krb5/files/patch-ai
Jacques Vidrine 3f37ef937e Security fix:
``Buffer overflows exist in the FTP daemon included with MIT krb5.''
See <URL:http://web.mit.edu/kerberos/www/advisories/ftpbuf.txt> and
<URL:http://web.mit.edu/kerberos/www/advisories/ftpbuf_122_patch.txt>.

Obtained from:	MIT Kerberos mailing list
2001-04-27 18:15:00 +00:00

288 lines
7.6 KiB
Plaintext

--- appl/gssftp/ftpd/ftpd.c.orig Wed Feb 28 16:06:45 2001
+++ appl/gssftp/ftpd/ftpd.c Fri Apr 27 10:18:01 2001
@@ -485,7 +485,13 @@
#ifndef LOG_DAEMON
#define LOG_DAEMON 0
#endif
- openlog("ftpd", LOG_PID | LOG_NDELAY, LOG_DAEMON);
+
+#ifndef LOG_FTP
+#define FACILITY LOG_DAEMON
+#else
+#define FACILITY LOG_FTP
+#endif
+ openlog("ftpd", LOG_PID | LOG_NDELAY, FACILITY);
addrlen = sizeof (his_addr);
if (getpeername(0, (struct sockaddr *)&his_addr, &addrlen) < 0) {
@@ -761,7 +767,16 @@
int result;
#ifdef GSSAPI
if (auth_type && strcmp(auth_type, "GSSAPI") == 0) {
+ int len;
authorized = ftpd_gss_userok(&client_name, name) == 0;
+ len = sizeof("GSSAPI user is not authorized as "
+ "; Password required.")
+ + strlen(client_name.value)
+ + strlen(name);
+ if (len >= sizeof(buf)) {
+ syslog(LOG_ERR, "user: username too long");
+ name = "[username too long]";
+ }
sprintf(buf, "GSSAPI user %s is%s authorized as %s",
client_name.value, authorized ? "" : " not",
name);
@@ -772,7 +787,18 @@
#endif /* GSSAPI */
#ifdef KRB5_KRB4_COMPAT
if (auth_type && strcmp(auth_type, "KERBEROS_V4") == 0) {
+ int len;
authorized = kuserok(&kdata,name) == 0;
+ len = sizeof("Kerberos user .@ is not authorized as "
+ "; Password required.")
+ + strlen(kdata.pname)
+ + strlen(kdata.pinst)
+ + strlen(kdata.prealm)
+ + strlen(name);
+ if (len >= sizeof(buf)) {
+ syslog(LOG_ERR, "user: username too long");
+ name = "[username too long]";
+ }
sprintf(buf, "Kerberos user %s%s%s@%s is%s authorized as %s",
kdata.pname, *kdata.pinst ? "." : "",
kdata.pinst, kdata.prealm,
@@ -1179,6 +1205,11 @@
} else {
char line[FTP_BUFSIZ];
+ if (strlen(cmd) + strlen(name) + 1 >= sizeof(line)) {
+ syslog(LOG_ERR, "retrieve: filename too long");
+ reply(501, "filename too long");
+ return;
+ }
(void) sprintf(line, cmd, name), name = line;
fin = ftpd_popen(line, "r"), closefunc = ftpd_pclose;
st.st_size = -1;
@@ -1417,6 +1448,10 @@
return (file);
}
+/*
+ * XXX callers need to limit total length of output string to
+ * FTP_BUFSIZ
+ */
#ifdef STDARG
secure_error(char *fmt, ...)
#else
@@ -1616,13 +1651,19 @@
{
char line[FTP_BUFSIZ];
FILE *fin;
- int c;
+ int c, n;
char str[FTP_BUFSIZ], *p;
+ if (strlen(filename) + sizeof("/bin/ls -lgA ")
+ >= sizeof(line)) {
+ reply(501, "filename too long");
+ return;
+ }
(void) sprintf(line, "/bin/ls -lgA %s", filename);
fin = ftpd_popen(line, "r");
lreply(211, "status of %s:", filename);
p = str;
+ n = 0;
while ((c = getc(fin)) != EOF) {
if (c == '\n') {
if (ferror(stdout)){
@@ -1639,7 +1680,16 @@
*p = '\0';
reply(0, "%s", str);
p = str;
- } else *p++ = c;
+ n = 0;
+ } else {
+ *p++ = c;
+ n++;
+ if (n >= sizeof(str)) {
+ reply(551, "output line too long");
+ (void) ftpd_pclose(fin);
+ return;
+ }
+ }
}
if (p != str) {
*p = '\0';
@@ -1723,6 +1773,10 @@
char cont_char = ' ';
+/*
+ * XXX callers need to limit total length of output string to
+ * FTP_BUFSIZ bytes for now.
+ */
#ifdef STDARG
reply(int n, char *fmt, ...)
#else
@@ -1744,22 +1798,32 @@
#endif
if (auth_type) {
- char in[FTP_BUFSIZ], out[FTP_BUFSIZ];
+ /*
+ * Deal with expansion in mk_{safe,priv},
+ * radix_encode, gss_seal, plus slop.
+ */
+ char in[FTP_BUFSIZ*3/2], out[FTP_BUFSIZ*3/2];
int length, kerror;
if (n) sprintf(in, "%d%c", n, cont_char);
else in[0] = '\0';
strncat(in, buf, sizeof (in) - strlen(in) - 1);
#ifdef KRB5_KRB4_COMPAT
if (strcmp(auth_type, "KERBEROS_V4") == 0) {
- if ((length = clevel == PROT_P ?
- krb_mk_priv((unsigned char *)in,
- (unsigned char *)out,
- strlen(in), schedule, &kdata.session,
- &ctrl_addr, &his_addr)
- : krb_mk_safe((unsigned char *)in,
- (unsigned char *)out,
- strlen(in), &kdata.session,
- &ctrl_addr, &his_addr)) == -1) {
+ if (clevel == PROT_P)
+ length = krb_mk_priv((unsigned char *)in,
+ (unsigned char *)out,
+ strlen(in),
+ schedule, &kdata.session,
+ &ctrl_addr,
+ &his_addr);
+ else
+ length = krb_mk_safe((unsigned char *)in,
+ (unsigned char *)out,
+ strlen(in),
+ &kdata.session,
+ &ctrl_addr,
+ &his_addr);
+ if (length == -1) {
syslog(LOG_ERR,
"krb_mk_%s failed for KERBEROS_V4",
clevel == PROT_P ? "priv" : "safe");
@@ -1803,13 +1867,16 @@
}
#endif /* GSSAPI */
/* Other auth types go here ... */
- if (kerror = radix_encode(out, in, &length, 0)) {
+ if (length >= sizeof(in) / 4 * 3) {
+ syslog(LOG_ERR, "input to radix_encode too long");
+ fputs(in, stdout);
+ } else if (kerror = radix_encode(out, in, &length, 0)) {
syslog(LOG_ERR, "Couldn't encode reply (%s)",
radix_error(kerror));
fputs(in,stdout);
} else
- printf("%s%c%s", clevel == PROT_P ? "632" : "631",
- n ? cont_char : '-', in);
+ printf("%s%c%s", clevel == PROT_P ? "632" : "631",
+ n ? cont_char : '-', in);
} else {
if (n) printf("%d%c", n, cont_char);
fputs(buf, stdout);
@@ -1822,6 +1889,10 @@
}
}
+/*
+ * XXX callers need to limit total length of output string to
+ * FTP_BUFSIZ
+ */
#ifdef STDARG
lreply(int n, char *fmt, ...)
#else
@@ -1866,7 +1937,8 @@
if (cp = strchr(cbuf,'\n'))
*cp = '\0';
- reply(500, "'%s': command not understood.", cbuf);
+ reply(500, "'%.*s': command not understood.",
+ FTP_BUFSIZ - sizeof("'': command not understood."), cbuf);
}
delete_file(name)
@@ -2143,7 +2215,21 @@
int code;
char *string;
{
- reply(code, "%s: %s.", string, strerror(errno));
+ char *err_string;
+ size_t extra_len;
+ err_string = strerror(errno);
+ if (err_string == NULL)
+ err_string = "(unknown error)";
+ extra_len = strlen(err_string) + sizeof("(truncated): .");
+ /*
+ * XXX knows about FTP_BUFSIZ in reply()
+ */
+ if (strlen(string) + extra_len > FTP_BUFSIZ) {
+ reply(code, "(truncated)%.*s: %s.",
+ FTP_BUFSIZ - extra_len, string, err_string);
+ } else {
+ reply(code, "%s: %s.", string, err_string);
+ }
}
auth(type)
@@ -2226,6 +2312,10 @@
secure_error("ADAT: krb_mk_safe failed");
return(0);
}
+ if (length >= (FTP_BUFSIZ - sizeof("ADAT=")) / 4 * 3) {
+ secure_error("ADAT: reply too long");
+ return(0);
+ }
if (kerror = radix_encode(out_buf, buf, &length, 0)) {
secure_error("Couldn't encode ADAT reply (%s)",
radix_error(kerror));
@@ -2360,6 +2450,16 @@
}
if (out_tok.length) {
+ if (out_tok.length >= ((FTP_BUFSIZ - sizeof("ADAT="))
+ / 4 * 3)) {
+ secure_error("ADAT: reply too long");
+ syslog(LOG_ERR, "ADAT: reply too long");
+ (void) gss_release_cred(&stat_min, &server_creds);
+ if (ret_flags & GSS_C_DELEG_FLAG)
+ (void) gss_release_cred(&stat_min,
+ &deleg_creds);
+ return(0);
+ }
if (kerror = radix_encode(out_tok.value, gbuf, &out_tok.length, 0)) {
secure_error("Couldn't encode ADAT reply (%s)",
radix_error(kerror));
@@ -2458,6 +2558,9 @@
* n>=0 on success
* -1 on error
* -2 on security error
+ *
+ * XXX callers need to limit total length of output string to
+ * FTP_BUFSIZ
*/
#ifdef STDARG
secure_fprintf(FILE *stream, char *fmt, ...)
@@ -2575,6 +2678,15 @@
dir->d_name[2] == '\0')
continue;
+ if (strlen(dirname) + strlen(dir->d_name)
+ + 1 /* slash */
+ + 2 /* CRLF */
+ + 1 > sizeof(nbuf)) {
+ syslog(LOG_ERR,
+ "send_file_list: pathname too long");
+ ret = -2; /* XXX */
+ goto data_err;
+ }
sprintf(nbuf, "%s/%s", dirname, dir->d_name);
/*