Vulnerability Name:

CVE-2020-12884 (CCN-183640)

Assigned:2020-05-12
Published:2020-05-12
Updated:2020-06-25
Summary: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 v3 Severity:9.1 Critical (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H)
7.9 High (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): None
Availibility (A): High
5.3 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)
4.6 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Low
CVSS v2 Severity:6.4 Medium (CVSS v2 Vector: AV:N/AC:L/Au:N/C:P/I:N/A:P)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): Partial
Integrity (I): None
Availibility (A): Partial
5.0 Medium (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Partial
Vulnerability Type:CWE-125
Vulnerability Consequences:Denial of Service
References:Source: MITRE
Type: CNA
CVE-2020-12884

Source: XF
Type: UNKNOWN
armmbed-cve202012884-dos(183640)

Source: CONFIRM
Type: Third Party Advisory
https://github.com/ARMmbed/mbed-coap/pull/116

Source: CCN
Type: Mbed OS GIT Repository
Out of range memory access in MbedOS CoAP library parser - sn_coap_parser_options_parse_multiple_options #12928

Source: MISC
Type: Third Party Advisory
https://github.com/ARMmbed/mbed-os/issues/12928

Source: CCN
Type: WhiteSource Vulnerability Database
CVE-2020-12884

Vulnerable Configuration:Configuration 1:
  • cpe:/o:arm:mbed_os:5.15.3:*:*:*:*:*:*:*

    • Configuration CCN 1:
  • cpe:/o:arm:mbed_os:5.15.3:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    BACK
    arm mbed os 5.15.3
    arm mbed os 5.15.3