#VU44426 NULL pointer dereference in CODESYS - CVE-2011-5009

Vulnerability identifier: #VU44426

Vulnerability risk: Medium

CVSSv4.0: 5.5 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2011-5009

CWE-ID: CWE-476

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
CODESYS
Server applications / Web servers

Vendor: CODESYS

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error. A remote attacker can trigger denial of service conditions via (1) a crafted Content-Length in an HTTP POST or (2) an invalid HTTP request method.

Mitigation
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

CODESYS: 3.4

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External links
https://aluigi.altervista.org/adv/codesys_1-adv.txt
https://seclists.org/bugtraq/2011/Nov/178
https://secunia.com/advisories/47018
https://www.osvdb.org/77388
https://www.osvdb.org/77389
https://www.us-cert.gov/control_systems/pdf/ICS-ALERT-11-336-01A.pdf
https://exchange.xforce.ibmcloud.com/vulnerabilities/71533

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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.