CVE-2021-31878

mediumpriority · track · 27EPSS 0.025 · 84 %ileDEEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

2.46% (84th) EPSS

CVSS 4 · medium

Is it mine?

19 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

An issue was discovered in PJSIP in Asterisk before 16.19.1 and before 18.5.1. To exploit, a re-INVITE without SDP must be received after Asterisk has sent a BYE request.

cvss

Technical severity, 0–10. One row per scoring source.

6.5

010

base score 0–10 · higher = more severe · hover a vector to decode

v2.04mediumAV:N/AC:L/Au:S/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 8 · impact 2.9

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 2.8 · impact 3.6

v3.16.5mediumAV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.16mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-617USprimaryCWE-617US

affected products (19)

Products and version ranges known to be affected.

Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
Gentoo Linuxall versionscert_bundDEcpe:/o:gentoo:linux:-
Open Source Asterisk <16.19.1all versionscert_bundDE
Open Source Asterisk <18.5.1all versionscert_bundDE
Ubuntu Linuxall versionscert_bundDEcpe:/o:canonical:ubuntu_linux:-
Open Source Asterisk< 16.19.1cert_bundDE
Open Source Asterisk< 18.5.1cert_bundDE
n/a n/a≤ n/aenisa_euvdEU
Digium, Inc. Asterisk16.17.0 → 16.19.1fstec_bduRU
Digium, Inc. Asterisk18.3.0 → 18.5.1fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 10fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 11fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 9fstec_bduRU
digium asterisk= 16.17.0nvdUScpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*
digium asterisk= 16.18.0nvdUScpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*
digium asterisk= 16.19.0nvdUScpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*
digium asterisk= 18.3.0nvdUScpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*
digium asterisk= 18.4.0nvdUScpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*
digium asterisk= 18.5.0nvdUScpe:2.3:a:digium:asterisk:*:*:*:*:*:*:*:*

advisories (1)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2024-3631Asterisk: Mehrere Schwachstellen ermöglichen Denial of ServiceDeutsch2021-07-22csaf · cert_bundDE
Ein entfernter, authentisierter oder anonymer Angreifer kann mehrere Schwachstellen in Asterisk ausnutzen, um einen Denial of Service Angriff durchzuführen.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund nvd NVD CVE.org MITRE

published 2021-07-30modified 2026-06-17

related (1,031)

Related entries.

ID	severity	EPSS	exploitable	published
CVE-2015-5477US	high7.8OT critical	99.6% (100th)	KEV	2015-07-29
named in ISC BIND 9.x before 9.9.7-P2 and 9.10.x before 9.10.2-P3 allows remote attackers to cause a denial of service (REQUIRE assertion failure and daemon exit) via TKEY queries.
CVE-2016-2776US	high7.5	89.5% (100th)	Exploit	2016-09-28
buffer.c in named in ISC BIND 9 before 9.9.9-P3, 9.10.x before 9.10.4-P3, and 9.11.x before 9.11.0rc3 does not properly construct responses, which allows remote attackers to cause…
CVE-2021-25216US	critical9.8	83.0% (100th)	—	2021-04-29
In BIND 9.5.0 -> 9.11.29, 9.12.0 -> 9.16.13, and versions BIND 9.11.3-S1 -> 9.11.29-S1 and 9.16.8-S1 -> 9.16.13-S1 of BIND Supported Preview Edition, as well as release versions 9.…
CVE-2020-8617US	medium5.9	93.4% (100th)	Exploit	2020-05-19
Using a specially-crafted message, an attacker may potentially cause a BIND server to reach an inconsistent state if the attacker knows (or successfully guesses) the name of a TSIG…
CVE-2018-5740US	high7.5	59.6% (99th)	Exploit	2019-01-16
"deny-answer-aliases" is a little-used feature intended to help recursive server operators protect end users against DNS rebinding attacks, a potential method of circumventing the…

+1026 more

references (18)

External citations — patches, advisories, analysis.

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