Vulnerability in Amcrest Ipm-721s

CVE-2017-8227

Amcrest IPM-721S V2.420.AC00.16.R.20160909 devices have a timeout policy to wait for 5 minutes in case 30 incorrect password attempts are detected using the Web and HTTP API interface provided by the device. However, if the same brute force attempt is performed using the ONVIF specification (which is supported by the same binary) then there is no account lockout or timeout executed. This can allow an attacker to circumvent the account protection mechanism and brute force the credentials. If the firmware version V2.420.AC00.16.R 9/9/2016 is dissected using binwalk tool, one obtains a _user-x.squashfs.img.extracted archive which contains the filesystem set up on the device that many of the binaries in the /usr folder. The binary "sonia" is the one that has the vulnerable function that performs the credential check in the binary for the ONVIF specification. If one opens this binary in IDA-pro one will notice that this follows a ARM little endian format. The function at address 00671618 in IDA pro is parses the WSSE security token header. The sub_ 603D8 then performs the authentication check and if it is incorrect passes to the function sub_59F4C which prints the value "Sender not authorized."

EPSS: 0.041 (89.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

  • cve@mitre.org (mailing-list, x_refsource_BUGTRAQ, Mailing List, Third Party Advisory)
  • cve@mitre.org (VDB Entry, Third Party Advisory, x_refsource_MISC)
  • cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)

Frequently asked questions

What is CVE-2017-8227?
CVE-2017-8227 is a critical-severity vulnerability in Amcrest Ipm-721s, classified under CWE-254. CVSS score: 9.8/10. Published 2019-07-03.
How severe is CVE-2017-8227?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2017-8227 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.