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Fencer Vulns
high 8.6

CVE-2021-41145 json

FreeSWITCH susceptible to Denial of Service via SIP flooding

published 2021-10-25 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-28260

cvss
8.6
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.7%
EPSS 1.7% chance of exploitation in 30 days, percentile 76%
public exploits
0
none known

Summary

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.

Patch / fix

  • freeswitch freeswitch 1.10.7
  • freeswitch Alpine 3.24, Alpine 3.23, Alpine 3.22 +7 more 1.10.7-r0

alpine advisories ALPINE-CVE-2021-41145

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Exploit prediction

1.65% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/signalwire/freeswitch/security/advisories/GHSA-jvpq-23v4-gp3m referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

  • signalwire freeswitch

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-401 Missing Release of Memory after Effective Lifetime

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.