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CVE-2016-4303: The parse_string function in cjson.c in the cJSON library mishandles UTF8/16 strings, which allows remote…

CVE-2016-4303 is rated critical with a CVSS v3.1 base score of 9.8 and NVD lists 5 affected products, including Es Iperf3. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

The parse_string function in cjson.c in the cJSON library mishandles UTF8/16 strings, which allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a non-hex character in a JSON string, which triggers a heap-based buffer overflow.

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
Attack complexity: Low. No special conditions; the attack can be repeated reliably.
Privileges required: None. No account or prior access is needed.
User interaction: None. No action from any user is needed.
Scope: Unchanged. Impact stays within the vulnerable component.
Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-120: Buffer Copy without Checking Size of Input

The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.

Affected products

Es Iperf3: from 3.0 before 3.0.12; from 3.1 before 3.1.3
Novell Suse Package Hub For Suse Linux Enterprise: 12
Opensuse Leap: 42.1
Opensuse: 13.2
Debian Linux: 8.0