CVE-2021-41145
FreeSWITCH susceptible to Denial of Service via SIP flooding
FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. FreeSWITCH prior to version 1.10.7 is susceptible to Denial of Service via SIP flooding. When flooding FreeSWITCH with SIP messages, it was observed that after a number of seconds the process was killed by the operating system due to memory exhaustion. By abusing this vulnerability, an attacker is able to crash any FreeSWITCH instance by flooding it with SIP messages, leading to Denial of Service. The attack does not require authentication and can be carried out over UDP, TCP or TLS. This issue was patched in version 1.10.7.
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
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
FreeSWITCH susceptible to Denial of Service via SIP flooding
FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. FreeSWITCH prior to version 1.10.7 is susceptible to Denial of Service via SIP flooding. When flooding FreeSWITCH with SIP messages, it was observed that after a number of seconds the process was killed by the operating system due to memory exhaustion. By abusing this vulnerability, an attacker is able to crash any FreeSWITCH instance by flooding it with SIP messages, leading to Denial of Service. The attack does not require authentication and can be carried out over UDP, TCP or TLS. This issue was patched in version 1.10.7.
- Record
CVE-2021-41145- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H - Weakness
- CWE-400
- Updated
- 2026-11-02
EUVDEUVD-2021-28260
FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. FreeSWITCH prior to version 1.10.7 is susceptible to Denial of Service via SIP flooding. When flooding FreeSWITCH with SIP messages, it was observed that after a number of seconds the process was killed by the operating system due to memory exhaustion. By abusing this vulnerability, an attacker is able to crash any FreeSWITCH instance by flooding it with SIP messages, leading to Denial of Service. The attack does not require authentication and can be carried out over UDP, TCP or TLS. This issue was patched in version 1.10.7.
- Record
EUVD-2021-28260- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H - Updated
- 2026-11-03
NVD
FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. FreeSWITCH prior to version 1.10.7 is susceptible to Denial of Service via SIP flooding. When flooding FreeSWITCH with SIP messages, it was observed that after a number of seconds the process was killed by the operating system due to memory exhaustion. By abusing this vulnerability, an attacker is able to crash any FreeSWITCH instance by flooding it with SIP messages, leading to Denial of Service. The attack does not require authentication and can be carried out over UDP, TCP or TLS. This issue was patched in version 1.10.7.
- Record
CVE-2021-41145- CVSS 3.1
- 8.6 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-400, CWE-401
- Updated
- 2026-11-02
OSVALPINE-CVE-2021-41145
FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. FreeSWITCH prior to version 1.10.7 is susceptible to Denial of Service via SIP flooding. When flooding FreeSWITCH with SIP messages, it was observed that after a number of seconds the process was killed by the operating system due to memory exhaustion. By abusing this vulnerability, an attacker is able to crash any FreeSWITCH instance by flooding it with SIP messages, leading to Denial of Service. The attack does not require authentication and can be carried out over UDP, TCP or TLS. This issue was patched in version 1.10.7.
- Record
ALPINE-CVE-2021-41145- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSV
FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. FreeSWITCH prior to version 1.10.7 is susceptible to Denial of Service via SIP flooding. When flooding FreeSWITCH with SIP messages, it was observed that after a number of seconds the process was killed by the operating system due to memory exhaustion. By abusing this vulnerability, an attacker is able to crash any FreeSWITCH instance by flooding it with SIP messages, leading to Denial of Service. The attack does not require authentication and can be carried out over UDP, TCP or TLS. This issue was patched in version 1.10.7.
- Record
CVE-2021-41145- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
freeswitchAlpine:v3.15 |
before 1.10.7-r0 | 1.10.7-r0 |
freeswitchAlpine:v3.16 |
before 1.10.7-r0 | 1.10.7-r0 |
freeswitchAlpine:v3.17 |
before 1.10.7-r0 | 1.10.7-r0 |
freeswitchAlpine:v3.18 |
before 1.10.7-r0 | 1.10.7-r0 |
freeswitchAlpine:v3.19 |
before 1.10.7-r0 | 1.10.7-r0 |
freeswitchAlpine:v3.20 |
before 1.10.7-r0 | 1.10.7-r0 |
freeswitchAlpine:v3.21 |
before 1.10.7-r0 | 1.10.7-r0 |
freeswitchAlpine:v3.22 |
before 1.10.7-r0 | 1.10.7-r0 |
freeswitchAlpine:v3.23 |
before 1.10.7-r0 | 1.10.7-r0 |
freeswitchAlpine:v3.24 |
before 1.10.7-r0 | 1.10.7-r0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-41145 is a high vulnerability (CVSS 8.6) in Freeswitch, published October 25, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.65%, the 76th percentile. Fixed in freeswitch 1.10.7-r0.