SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2020-12886

A buffer over-read was discovered in the CoAP library in Arm Mbed OS 5.15.3.

CRITICAL 9.1EPSS 1.35%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.35%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

A buffer over-read was discovered in the CoAP library in Arm Mbed OS 5.15.3. The CoAP parser is responsible for parsing received CoAP packets. The function sn_coap_parser_options_parse() parses the CoAP packet header starting from the message token. The length of the token in the received message is provided in the first byte parsed by the sn_coap_parser_options_parse() function. The length encoded in the message is not validated against the actual input buffer length before accessing the token. As a result, memory access outside of the intended boundary of the buffer may occur.

CVSS 3.1
9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
EPSS
1.35% probability · 70th percentile
CISA KEV
Not listed
Weakness
CWE-125
Affected
arm/mbed os
Source
cve@mitre.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.