CVE-2020-35776 [Medium] | Memory Corruption in Asterisk

CVE-2020-35776 is rated Exploit Available (50/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.08%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

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#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-03-30	0.23%	0.08%	-0.15%
2	2025-03-29	0.08%	0.23%	+0.15%
3	2025-03-17	—	0.08%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-03-30

0.23%

0.08%

-0.15%

2025-03-29

0.08%

0.23%

+0.15%

2025-03-17

—

0.08%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
6.5	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	2.8	3.6	[email protected]
4.3	2.0	MEDIUM	`AV:N/AC:M/Au:N/C:N/I:N/A:P` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:N) No authentication is required. Confidentiality impact (C:N) No confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:P) Partial availability impact.	8.6	2.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

6.5

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

2.8

3.6

[email protected]

4.3

2.0

MEDIUM

AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:N): No confidentiality impact.
Integrity impact (I:N): No integrity impact.
Availability impact (A:P): Partial availability impact.

8.6

2.9

[email protected]

OS Trackers for CVE-2020-35776

vendor	priority	summary	link
`alpine`	medium	CVE-2020-35776: 1 source package rows (asterisk); 36 state rows across 10 repos (3.10-main, 3.11-main, 3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 8, open 28.	https://security.alpinelinux.org/vuln/CVE-2020-35776
`debian`	not yet assigned	CVE-2020-35776 not yet assigned priority: Debian including 1 source packages (asterisk), 2 status rows across 2 suites (bullseye, sid): resolved 2.	https://security-tracker.debian.org/tracker/CVE-2020-35776
`gentoo`	high	CVE-2020-35776: 1 GLSA(s) (202412-03), 1 atom(s) (net-misc/asterisk); latest impact high.	https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-35776
`ubuntu`	medium	CVE-2020-35776 medium priority: Ubuntu including 1 source packages (asterisk), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 8, needs-triage 7, DNE 1.	https://ubuntu.com/security/CVE-2020-35776

Affected software / configurations for CVE-2020-35776

Vendor	Product	Version	Raw CPE
digium	asterisk	>= 13.0.0, <= 13.38.1	cpe:2.3:a:digium:asterisk::::::::
digium	asterisk	>= 16.0.0, <= 16.15.1	cpe:2.3:a:digium:asterisk::::::::
digium	asterisk	>= 17.0.0, <= 17.9.1	cpe:2.3:a:digium:asterisk::::::::
digium	asterisk	>= 18.0, <= 18.1.1	cpe:2.3:a:digium:asterisk::::::::

References for CVE-2020-35776

URL	Tags
http://packetstormsecurity.com/files/161470/Asterisk-Project-Security-Advisory-AST-2021-001.html	Patch Third Party Advisory
http://seclists.org/fulldisclosure/2021/Feb/57	Mailing List Third Party Advisory
https://downloads.asterisk.org/pub/security/AST-2021-001.html	Vendor Advisory
https://issues.asterisk.org/	Issue Tracking Vendor Advisory
https://issues.asterisk.org/jira/browse/ASTERISK-29227	Exploit Issue Tracking Patch Vendor Advisory

URL

CVE-2020-35776

Public exploit references (Exploit-DB) for CVE-2020-35776

Exploit prediction scoring system (EPSS) score for CVE-2020-35776

Common vulnerability scoring system (CVSS) metrics for CVE-2020-35776

Weakness enumeration for CVE-2020-35776

OS Trackers for CVE-2020-35776

Affected software / configurations for CVE-2020-35776

References for CVE-2020-35776