PT-2020-13315 · Arm · Arm Mbed Os
Mjurczak
·
Published
2020-06-18
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Updated
2021-07-21
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CVE-2020-12883
CVSS v3.1
9.1
Critical
| Vector | AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H |
Name of the Vulnerable Software and Affected Versions
Arm Mbed OS version 5.15.3
Description
Buffer over-reads were discovered in the CoAP library. 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. 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. This leads to heap-based or stack-based memory location read access that is outside of the intended boundary of the buffer, potentially resulting in processing of unintended inputs or system memory access violation errors.Recommendations
For Arm Mbed OS version 5.15.3, as a temporary workaround, consider disabling the
sn coap parser options parse() function until a patch is available. Restrict access to the CoAP library to minimize the risk of exploitation. At the moment, there is no information about a newer version that contains a fix for this vulnerability.Out of bounds Read
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Weakness Enumeration
Related Identifiers
Affected Products
Arm Mbed Os