CVE-2020-35776

Gentoo Linux Security Advisory 202412-03

Severity Score

6.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

A buffer overflow in res_pjsip_diversion.c in Sangoma Asterisk versions 13.38.1, 16.15.1, 17.9.1, and 18.1.1 allows remote attacker to crash Asterisk by deliberately misusing SIP 181 responses.

Un desbordamiento del búfer en el archivo res_pjsip_diversion.c en Sangoma Asterisk versiones 13.38.1, 16.15.1, 17.9.1 y 18.1.1, permite a un atacante remoto bloquear Asterisk al hacer un uso inapropiado deliberadamente de las respuestas SIP 181

If a registered user is tricked into dialing a malicious number that sends lots of 181 responses to Asterisk, each one will cause a 181 to be sent back to the original caller with an increasing number of entries in the ???Supported??? header. Eventually the number of entries in the header exceeds the size of the entry array and causes a crash.

*Credits: N/A

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

None

Integrity

None

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2020-12-29 CVE Reserved
2021-02-18 CVE Published
2024-08-04 CVE Updated
2024-08-04 First Exploit
2025-03-30 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

CAPEC

References (5)

URL	Tag	Source
http://seclists.org/fulldisclosure/2021/Feb/57	Mailing List

URL	Date	SRC
https://issues.asterisk.org/jira/browse/ASTERISK-29227	2024-08-04

URL	Date	SRC
http://packetstormsecurity.com/files/161470/Asterisk-Project-Security-Advisory-AST-2021-001.html	2021-02-24

URL	Date	SRC
https://downloads.asterisk.org/pub/security/AST-2021-001.html	2021-02-24
https://issues.asterisk.org	2021-02-24

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Digium Search vendor "Digium"		Asterisk Search vendor "Digium" for product "Asterisk"				>= 13.0.0 <= 13.38.1 Search vendor "Digium" for product "Asterisk" and version " >= 13.0.0 <= 13.38.1"		-		Affected
Digium Search vendor "Digium"		Asterisk Search vendor "Digium" for product "Asterisk"				>= 16.0.0 <= 16.15.1 Search vendor "Digium" for product "Asterisk" and version " >= 16.0.0 <= 16.15.1"		-		Affected
Digium Search vendor "Digium"		Asterisk Search vendor "Digium" for product "Asterisk"				>= 17.0.0 <= 17.9.1 Search vendor "Digium" for product "Asterisk" and version " >= 17.0.0 <= 17.9.1"		-		Affected
Digium Search vendor "Digium"		Asterisk Search vendor "Digium" for product "Asterisk"				>= 18.0 <= 18.1.1 Search vendor "Digium" for product "Asterisk" and version " >= 18.0 <= 18.1.1"		-		Affected