CVE-2020-12884 | Date: (C)2020-06-19 (M)2023-12-22 |
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_multiple_options() parses CoAP options that may occur multiple consecutive times in a single packet. While processing the options, packet_data_pptr is accessed after being incremented by option_len without a prior out-of-bounds memory check. The temp_parsed_uri_query_ptr is validated for a correct range, but the range valid for temp_parsed_uri_query_ptr is derived from the amount of allocated heap memory, not the actual input size. Therefore the check of temp_parsed_uri_query_ptr may be insufficient for safe access to the area pointed to by packet_data_pptr. As a result, access to a memory area outside of the intended boundary of the packet buffer is made.
CVSS Score and Metrics +CVSS Score and Metrics -CVSS V3 Severity: | CVSS V2 Severity: |
CVSS Score : 9.1 | CVSS Score : 6.4 |
Exploit Score: 3.9 | Exploit Score: 10.0 |
Impact Score: 5.2 | Impact Score: 4.9 |
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CVSS V3 Metrics: | CVSS V2 Metrics: |
Attack Vector: NETWORK | Access Vector: NETWORK |
Attack Complexity: LOW | Access Complexity: LOW |
Privileges Required: NONE | Authentication: NONE |
User Interaction: NONE | Confidentiality: PARTIAL |
Scope: UNCHANGED | Integrity: NONE |
Confidentiality: HIGH | Availability: PARTIAL |
Integrity: NONE | |
Availability: HIGH | |
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