CVE-2021-43405: An issue was discovered in FusionPBX before 4.5.30. The fax_extension may have risky characters (it is not constrained to be numeric).

PriorityP267high8.8CVSS 3.1

AVNACLPRLUINSUCHIHAH

EXPLOIT

EPSS

35.63%

98.3th percentile

An issue was discovered in FusionPBX before 4.5.30. The fax_extension may have risky characters (it is not constrained to be numeric).

Affected

1 ranges

Vendor	Product	Version range	Fixed in
fusionpbx	fusionpbx	< 4.5.30	4.5.30

Detection & IOCsextracted from sources · hover to see the quote

→The vulnerable parameter is `fax_extension`, which is not constrained to numeric values and may contain risky/shell-injectable characters — monitor or filter non-numeric input to this field ↗
→This is an authenticated RCE vulnerability in FusionPBX 4.5.29 and earlier; detect authenticated POST requests to fax-related endpoints containing shell metacharacters in the fax_extension parameter ↗

·Exploitation requires valid credentials — this is an authenticated RCE; unauthenticated access alone is not sufficient to trigger the vulnerability ↗
·The vulnerability is fixed in FusionPBX 4.5.30 and later; versions before 4.5.30 are affected ↗

CVSS provenance

nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvdv2.06.5MEDIUMAV:N/AC:L/Au:S/C:P/I:P/A:P

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