ARM Mbed OS 5.15.3 CoAP Library sn_coap_parser_options_parse message_left memory corruption

Summaryinfo

A vulnerability identified as critical has been detected in ARM Mbed OS 5.15.3. The affected element is the function sn_coap_parser_options_parse of the component CoAP Library. Performing a manipulation of the argument message_left results in memory corruption. This vulnerability is identified as CVE-2020-12883. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in ARM Mbed OS 5.15.3. It has been classified as critical. This affects the function sn_coap_parser_options_parse of the component CoAP Library. The manipulation of the argument message_left with an unknown input leads to a memory corruption vulnerability. CWE is classifying the issue as CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Buffer over-reads were 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 CoAP input linearly using a while loop. Once an option is parsed in a loop, the current point (*packet_data_pptr) is increased correspondingly. The pointer is restricted by the size of the received buffer, as well as by the option delta and option length bytes. The actual input packet length is not verified against the number of bytes read when processing the option extended delta and the option extended length. Moreover, the calculation of the message_left variable, in the case of non-extended option deltas, is incorrect and indicates more data left for processing than provided in the function input. All of these lead to heap-based or stack-based memory location read access that is outside of the intended boundary of the buffer. Depending on the platform-specific memory management mechanisms, it can lead to processing of unintended inputs or system memory access violation errors.

The weakness was released 06/18/2020 (GitHub Repository). The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2020-12883 since 05/15/2020. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Entries connected to this vulnerability are available at VDB-156922, VDB-156923, VDB-156924 and VDB-156925. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• ARM

Name

• Mbed OS

Version

• 5.15.3

License

• commercial

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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