CVE-2021-21375

mediumpriority · track · 27EPSS 0.021 · 81 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

2.08% (81st) EPSS

CVSS 4.3 · medium

Is it mine?

3 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · nvd

EPSS · scored 2026-10-27

PJSIP is a free and open source multimedia communication library written in C language implementing standard based protocols such as SIP, SDP, RTP, STUN, TURN, and ICE. In PJSIP version 2.10 and earlier, after an initial INVITE has been sent, when two 183 responses are received, with the first one causing negotiation failure, a crash will occur. This results in a denial of service.

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

v2.04.3mediumAV:N/AC:M/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 8.6 · impact 2.9

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

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:Hsecondary · ENISA EU

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:Hsecondary · security-advisories@github.comexploitability 2.8 · impact 3.6

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

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-754USprimaryCWE-400US

affected products (3)

Products and version ranges known to be affected.

pjsip pjproject≤ ≤ 2.10enisa_euvdEU
debian debian linux= 9.0nvdUScpe:2.3:o:debian:debian_linux:*:*:*:*:*:*:*:*
teluu pjsip≤ 2.10nvdUScpe:2.3:a:teluu:pjsip:*:*:*:*:*:*:*:*

also known as (2)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd NVD CVE.org MITRE

published 2021-03-10modified 2026-06-17

related (782)

Related entries.

ID	severity	EPSS	exploitable	published
CVE-2025-39682US	critical9.8OT critical	3.25% (88th)	KEV	2025-09-05
In the Linux kernel, the following vulnerability has been resolved: tls: fix handling of zero-length records on the rx_list Each recvmsg() call must process either - only contig…
CVE-2024-3393US	high7.5OT critical	29.1% (98th)	KEV	2024-12-27
A Denial of Service vulnerability in the DNS Security feature of Palo Alto Networks PAN-OS software allows an unauthenticated attacker to send a malicious packet through the data p…
CVE-2023-41993US	high8.8OT critical	24.3% (98th)	KEV	2023-09-21
The issue was addressed with improved checks. This issue is fixed in macOS Sonoma 14. Processing web content may lead to arbitrary code execution. Apple is aware of a report that t…
CVE-2023-41992US	high7.8OT critical	9.52% (95th)	KEV	2023-09-21
The issue was addressed with improved checks. This issue is fixed in macOS Monterey 12.7, iOS 16.7 and iPadOS 16.7, macOS Ventura 13.6. A local attacker may be able to elevate thei…
CVE-2021-3560US	high7.8OT critical	23.7% (98th)	KEV	2022-02-16
It was found that polkit could be tricked into bypassing the credential checks for D-Bus requests, elevating the privileges of the requestor to the root user. This flaw could be us…

+777 more

references (20)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan