CVE-2021-37706
Potential integer underflow upon receiving STUN message in PJSIP
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 affected versions if the incoming STUN message contains an ERROR-CODE attribute, the header length is not checked before performing a subtraction operation, potentially resulting in an integer underflow scenario. This issue affects all users that use STUN. A malicious actor located within the victim’s network may forge and send a specially crafted UDP (STUN) message that could remotely execute arbitrary code on the victim’s machine. Users are advised to upgrade as soon as possible. There are no known workarounds.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
7.3
Potential integer underflow upon receiving STUN message in PJSIP
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 affected versions if the incoming STUN message contains an ERROR-CODE attribute, the header length is not checked before performing a subtraction operation, potentially resulting in an integer underflow scenario. This issue affects all users that use STUN. A malicious actor located within the victim’s network may forge and send a specially crafted UDP (STUN) message that could remotely execute arbitrary code on the victim’s machine. Users are advised to upgrade as soon as possible. There are no known workarounds.
- Record
CVE-2021-37706- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - Weakness
- CWE-191
- Updated
- 2026-11-02
EUVDEUVD-2021-24195
7.3
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 affected versions if the incoming STUN message contains an ERROR-CODE attribute, the header length is not checked before performing a subtraction operation, potentially resulting in an integer underflow scenario. This issue affects all users that use STUN. A malicious actor located within the victim’s network may forge and send a specially crafted UDP (STUN) message that could remotely execute arbitrary code on the victim’s machine. Users are advised to upgrade as soon as possible. There are no known workarounds.
- Record
EUVD-2021-24195- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - Updated
- 2026-11-02
NVD
7.3
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 affected versions if the incoming STUN message contains an ERROR-CODE attribute, the header length is not checked before performing a subtraction operation, potentially resulting in an integer underflow scenario. This issue affects all users that use STUN. A malicious actor located within the victim’s network may forge and send a specially crafted UDP (STUN) message that could remotely execute arbitrary code on the victim’s machine. Users are advised to upgrade as soon as possible. There are no known workarounds.
- Record
CVE-2021-37706- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 9.3 High
AV:N/AC:M/Au:N/C:C/I:C/A:C - Weakness
- CWE-191
- Updated
- 2026-11-02
OSVALPINE-CVE-2021-37706
9.8
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 affected versions if the incoming STUN message contains an ERROR-CODE attribute, the header length is not checked before performing a subtraction operation, potentially resulting in an integer underflow scenario. This issue affects all users that use STUN. A malicious actor located within the victim’s network may forge and send a specially crafted UDP (STUN) message that could remotely execute arbitrary code on the victim’s machine. Users are advised to upgrade as soon as possible. There are no known workarounds.
- Record
ALPINE-CVE-2021-37706- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSV
9.8
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 affected versions if the incoming STUN message contains an ERROR-CODE attribute, the header length is not checked before performing a subtraction operation, potentially resulting in an integer underflow scenario. This issue affects all users that use STUN. A malicious actor located within the victim’s network may forge and send a specially crafted UDP (STUN) message that could remotely execute arbitrary code on the victim’s machine. Users are advised to upgrade as soon as possible. There are no known workarounds.
- Record
CVE-2021-37706- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-37706
9.8
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 affected versions if the incoming STUN message contains an ERROR-CODE attribute, the header length is not checked before performing a subtraction operation, potentially resulting in an integer underflow scenario. This issue affects all users that use STUN. A malicious actor located within the victim’s network may forge and send a specially crafted UDP (STUN) message that could remotely execute arbitrary code on the victim’s machine. Users are advised to upgrade as soon as possible. There are no known workarounds.
- Record
DEBIAN-CVE-2021-37706- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-37706
7.3
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 affected versions if the incoming STUN message contains an ERROR-CODE attribute, the header length is not checked before performing a subtraction operation, potentially resulting in an integer underflow scenario. This issue affects all users that use STUN. A malicious actor located within the victim’s network may forge and send a specially crafted UDP (STUN) message that could remotely execute arbitrary code on the victim’s machine. Users are advised to upgrade as soon as possible. There are no known workarounds.
- Record
UBUNTU-CVE-2021-37706- CVSS 3.1
- 7.3 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUSN-6422-1 No score
ring vulnerabilities
It was discovered that Ring incorrectly handled certain inputs. If a user or an automated system were tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to execute arbitrary code. (CVE-2021-37706)
It was discovered that Ring incorrectly handled certain inputs. If a user or an automated system were tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. (CVE-2021-43299, CVE-2021-43300, CVE-2021-43301, CVE-2021-43302, CVE-2021-43303, CVE-2021-43804, CVE-2021-43845, CVE-2022-21723, CVE-2022-23537, CVE-2022-23547, CVE-2022-23608, CVE-2022-24754, CVE-2022-24763, CVE-2022-24764, CVE-2022-24793, CVE-2022-31031, CVE-2022-39244)
It was discovered that Ring incorrectly handled certain inputs. If a user or an automated system were tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 20.04 LTS. (CVE-2022-21722)
It was discovered that Ring incorrectly handled certain inputs. If a user or an automated system were tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to cause a denial of service. (CVE-2023-27585)
- Record
USN-6422-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
pjprojectAlpine:v3.16 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.17 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.18 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.19 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.20 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.21 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.22 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.23 |
before 2.12-r0 | 2.12-r0 |
pjprojectAlpine:v3.24 |
before 2.12-r0 | 2.12-r0 |
asteriskDebian:14 |
before 1:18.10.1~dfsg+~cs6.10.40431411-1, plus listed versions 0.1.11-30.1.11-3woody11:1.0.5-21:1.0.5-41:1.0.6-1 Show 45 moreShow less1:1.0.6-21:1.0.7-11:1.0.7.dfsg.1-11:1.0.7.dfsg.1-21:1.0.7.dfsg.1-2sarge11:1.0.7.dfsg.1-2sarge21:1.0.7.dfsg.1-2sarge31:1.0.7.dfsg.1-2sarge41:1.0.7.dfsg.1-2sarge51:1.0.7.dfsg.1-2sarge61:1.0.9.dfsg-11:1.0.9.dfsg-31:1.0.9.dfsg-41:1.0.9.dfsg-51:1.0.9.dfsg-61:1.2.0-beta1.dfsg-11:1.2.0-beta2.dfsg-11:1.2.0-beta2.dfsg-21:1.2.0-beta2.dfsg-31:1.2.0-rc1.dfsg-11:1.2.0-rc2.dfsg-11:1.2.0.dfsg-11:1.2.0.dfsg-21:1.2.0.dfsg-31:1.2.0.dfsg-41:1.2.0.dfsg-51:1.2.0.dfsg-61:1.2.1.dfsg-11:1.2.1.dfsg-21:1.2.1.dfsg-31:1.2.10.dfsg-11:1.2.10.dfsg-1bpo11:1.2.10.dfsg-21:1.2.10.dfsg-31:1.2.11.dfsg-11:1.2.12.1.dfsg-11:1.2.13~dfsg-11:1.2.13~dfsg-21:1.2.13~dfsg-2etch11:1.2.13~dfsg-2etch21:1.2.13~dfsg-2etch31:1.2.13~dfsg-2etch41:1.2.14~dfsg-11:1.2.14~dfsg-21:1.2.14~dfsg-3 |
1:18.10.1~dfsg+~cs6.10.40431411-1 |
Show 10 moreShow less
| Package | Affected | Fixed |
|---|---|---|
ringDebian:12 |
before 20230206.0~ds1-1 | 20230206.0~ds1-1 |
pjprojectDebian:9 |
before 2.5.5~dfsg-6+deb9u3, plus listed versions 2.5.5~dfsg-62.5.5~dfsg-6+deb9u12.5.5~dfsg-6+deb9u2 |
2.5.5~dfsg-6+deb9u3 |
asteriskDebian:10 |
before 1:16.28.0~dfsg-0+deb10u1, plus listed versions 1:16.10.0~dfsg-11:16.12.0~dfsg-11:16.15.0~dfsg-11:16.15.1~dfsg-11:16.16.1~dfsg+~2.10-1 Show 14 moreShow less1:16.16.1~dfsg+~2.10-21:16.16.1~dfsg-11:16.16.1~dfsg-1~bpo10+11:16.16.1~dfsg-21:16.16.1~dfsg-31:16.16.1~dfsg-41:16.2.1~dfsg-11:16.2.1~dfsg-1+deb10u11:16.2.1~dfsg-1+deb10u21:16.2.1~dfsg-21:16.23.0~dfsg+~2.10-11:16.23.0~dfsg+~cs6.10.20220309-11:16.23.0~dfsg+~cs6.10.20220309-21:16.23.0~dfsg+~cs6.10.40431411-1 |
1:16.28.0~dfsg-0+deb10u1 |
ringDebian:10 |
before 20190215.1.f152c98~ds1-1+deb10u2, plus listed versions 20190215.1.f152c98~ds1-120190215.1.f152c98~ds1-1+deb10u1 |
20190215.1.f152c98~ds1-1+deb10u2 |
ringDebian:11 |
before 20210112.2.b757bac~ds1-1+deb11u1, plus listed versions 20210112.2.b757bac~ds1-1 |
20210112.2.b757bac~ds1-1+deb11u1 |
asteriskDebian:11 |
before 1:16.28.0~dfsg-0+deb11u1, plus listed versions 1:16.16.1~dfsg+~2.10-11:16.16.1~dfsg+~2.10-21:16.16.1~dfsg-11:16.16.1~dfsg-1+deb11u11:16.16.1~dfsg-1+deb11u1~bpo10+1 Show 7 moreShow less1:16.16.1~dfsg-21:16.16.1~dfsg-31:16.16.1~dfsg-41:16.23.0~dfsg+~2.10-11:16.23.0~dfsg+~cs6.10.20220309-11:16.23.0~dfsg+~cs6.10.20220309-21:16.23.0~dfsg+~cs6.10.40431411-1 |
1:16.28.0~dfsg-0+deb11u1 |
pjprojectUbuntu:Pro:16.04:LTS |
before 2.1.0.0.ast20130823-1+deb8u1ubuntu0.1~esm1, plus listed versions 2.1.0.0.ast20130823-12.1.0.0.ast20130823-1+deb8u1build0.16.04.1 |
2.1.0.0.ast20130823-1+deb8u1ubuntu0.1~esm1 |
pjprojectUbuntu:Pro:18.04:LTS |
before 2.7.2~dfsg-1ubuntu0.1~esm1, plus listed versions 2.6~dfsg-22.7~dfsg-12.7.1~dfsg-12.7.1~dfsg-1build12.7.2~dfsg-1 |
2.7.2~dfsg-1ubuntu0.1~esm1 |
ringUbuntu:Pro:18.04:LTS |
before 20180228.1.503da2b~ds1-1ubuntu0.1~esm1, plus listed versions 20170803.2.5fcfe3f~dfsg1-120171024.1.eadbdeb~ds1-120171129.2.cf5bbff~ds1-120171129.2.cf5bbff~ds1-220180119.1.9e06f94~ds1-1 Show 4 moreShow less20180119.1.9e06f94~ds1-320180222.1.7bffde2~ds2-220180228.1.503da2b~ds1-120180228.1.503da2b~ds1-1build1 |
20180228.1.503da2b~ds1-1ubuntu0.1~esm1 |
ringUbuntu:20.04:LTS |
before 20190215.1.f152c98~ds1-1+deb10u2build0.20.04.1, plus listed versions 20190215.1.f152c98~ds1-120190215.1.f152c98~ds1-1build120190215.1.f152c98~ds1-1build2 |
20190215.1.f152c98~ds1-1+deb10u2build0.20.04.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-37706 is a high vulnerability (CVSS 7.3) in Teluu Pjsip, published December 22, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 4.92%, the 92nd percentile. Fixed in pjproject 2.12-r0.
References
github.com/pjsip/pjproject/security/advisories/GHSA-2qpg-f6wf-w984
github.com/pjsip/pjproject/commit/15663e3f37091069b8c98a7fce680dc04bc8e865
seclists.org/fulldisclosure/2022/Mar/0
packetstormsecurity.com/files/166225/Asterisk-Project-Security-Advisory-AST-2022-004.html
lists.debian.org/debian-lts-announce/2022/03/msg00035.html
security.gentoo.org/glsa/202210-37
Show 30 moreShow less
lists.debian.org/debian-lts-announce/2022/11/msg00021.html
debian.org/security/2022/dsa-5285
lists.debian.org/debian-lts-announce/2023/08/msg00038.html
lists.debian.org/debian-lts-announce/2024/09/msg00030.html
security.alpinelinux.org/vuln/CVE-2021-37706
security-tracker.debian.org/tracker/CVE-2021-37706
ubuntu.com/security/CVE-2021-37706
ubuntu.com/security/notices/USN-6422-1
ubuntu.com/security/notices/USN-6422-2
cve.org/CVERecord?id=CVE-2021-37706
ubuntu.com/security/notices/USN-8122-1
ubuntu.com/security/CVE-2021-43299
ubuntu.com/security/CVE-2021-43300
ubuntu.com/security/CVE-2021-43301
ubuntu.com/security/CVE-2021-43302
ubuntu.com/security/CVE-2021-43303
ubuntu.com/security/CVE-2021-43804
ubuntu.com/security/CVE-2021-43845
ubuntu.com/security/CVE-2022-21722
ubuntu.com/security/CVE-2022-21723
ubuntu.com/security/CVE-2022-23537
ubuntu.com/security/CVE-2022-23547
ubuntu.com/security/CVE-2022-23608
ubuntu.com/security/CVE-2022-24754
ubuntu.com/security/CVE-2022-24763
ubuntu.com/security/CVE-2022-24764
ubuntu.com/security/CVE-2022-24793
ubuntu.com/security/CVE-2022-31031
ubuntu.com/security/CVE-2022-39244
ubuntu.com/security/CVE-2023-27585
Left out here: 200 versions. The JSON record has them.