CVE-2019-5185: An exploitable stack buffer overflow vulnerability vulnerability exists in the iocheckd service "I/O-Check" functionality of WAGO PFC 200. An attacker...

Description

An exploitable stack buffer overflow vulnerability vulnerability exists in the iocheckd service "I/O-Check" functionality of WAGO PFC 200. An attacker can send a specially crafted packet to trigger the parsing of this cache file. At 0x1ea28 the extracted state value from the xml file is used as an argument to /etc/config-tools/config_interfaces interface=X1 state=<contents of state node> using sprintf(). The destination buffer sp+0x40 is overflowed with the call to sprintf() for any state values that are greater than 512-len("/etc/config-tools/config_interfaces interface=X1 state=") in length. Later, at 0x1ea08 strcpy() is used to copy the contents of the stack buffer that was overflowed sp+0x40 into sp+0x440. The buffer sp+0x440 is immediately adjacent to sp+0x40 on the stack. Therefore, there is no NULL termination on the buffer sp+0x40 since it overflowed into sp+0x440. The strcpy() will result in invalid memory access. An state value of length 0x3c9 will cause the service to crash.

Metrics

CVSS 3.1

7/10

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.85%

53.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
Wago	Pfc200 Firmware	03.02.02\(14\)

References

https://talosintelligence.com/vulnerability_reports/TALOS-2019-0966Exploit, Third Party Advisory
https://talosintelligence.com/vulnerability_reports/TALOS-2019-0966Exploit, Third Party Advisory

Timeline

Published: Mar 23, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-5185?

An exploitable stack buffer overflow vulnerability vulnerability exists in the iocheckd service "I/O-Check" functionality of WAGO PFC 200. An attacker can send a specially crafted packet to trigger the parsing of this cache file. At 0x1ea28 the extracted state value from the xml file is used as an argument to /etc/config-tools/config_interfaces interface=X1 state=<contents of state node> using sprintf(). The destination buffer sp+0x40 is overflowed with the call to sprintf() for any state values that are greater than 512-len("/etc/config-tools/config_interfaces interface=X1 state=") in length. Later, at 0x1ea08 strcpy() is used to copy the contents of the stack buffer that was overflowed sp+0x40 into sp+0x440. The buffer sp+0x440 is immediately adjacent to sp+0x40 on the stack. Therefore, there is no NULL termination on the buffer sp+0x40 since it overflowed into sp+0x440. The strcpy() will result in invalid memory access. An state value of length 0x3c9 will cause the service to crash.

How severe is CVE-2019-5185?

CVE-2019-5185 has a CVSS score of 7/10 (HIGH severity). The EPSS model estimates a 0.85% probability of exploitation in the next 30 days.

How do I fix CVE-2019-5185?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.