Vulnerability CVE-2021-26717

Vulnerability Name:

CVE-2021-26717 (CCN-197035)

Assigned:

2020-12-08

Published:

2020-12-08

Updated:

2021-02-24

Summary:

An issue was discovered in Sangoma Asterisk 16.x before 16.16.1, 17.x before 17.9.2, and 18.x before 18.2.1 and Certified Asterisk before 16.8-cert6. When re-negotiating for T.38, if the initial remote response was delayed just enough, Asterisk would send both audio and T.38 in the SDP. If this happened, and the remote responded with a declined T.38 stream, then Asterisk would crash.

CVSS v3 Severity:

7.5 High (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
6.5 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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): None Integrity (I): None Availibility (A): High

7.5 High (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
6.5 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: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): None Integrity (I): None Availibility (A): High

CVSS v2 Severity:

5.0 Medium (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 Authentication (Au): None
Impact Metrics:	Confidentiality (C): None Integrity (I): None Availibility (A): Partial

7.8 High (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C)

Exploitability Metrics:	Access Vector (AV): Network Access Complexity (AC): Low Athentication (Au): None
Impact Metrics:	Confidentiality (C): None Integrity (I): None Availibility (A): Complete