Vulnerability · Published Dec 27, 2023 · Assigned by GitHub_M
CVE-2023-51443FreeSWITCH susceptible to Denial of Service via DTLS Hello packets during call initiation
High 7.5
In plain English
A high-severity security flaw in freeswitch from signalwire. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 1.5% (higher than 74% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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. Prior to version 1.10.11, when handling DTLS-SRTP for media setup, FreeSWITCH is susceptible to Denial of Service due to a race condition in the hello handshake phase of the DTLS protocol. This attack can be done continuously, thus denying new DTLS-SRTP encrypted calls during the attack. If an attacker manages to send a ClientHello DTLS message with an invalid CipherSuite (such as `TLS_NULL_WITH_NULL_NULL`) to the port on the FreeSWITCH server that is expecting packets from the caller, a DTLS error is generated. This results in the media session being torn down, which is followed by teardown at signaling (SIP) level too. Abuse of this vulnerability may lead to a massive Denial of Service on vulnerable FreeSWITCH servers for calls that rely on DTLS-SRTP. To address this vulnerability, upgrade FreeSWITCH to 1.10.11 which includes the security fix. The solution implemented is to drop all packets from addresses that have not been validated by an ICE check.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | freeswitch | 1.10.11-r0 | ALPINE-CVE-2023-51443 |
| Alpine:v3.21 | freeswitch | 1.10.11-r0 | ALPINE-CVE-2023-51443 |
| Alpine:v3.22 | freeswitch | 1.10.11-r0 | ALPINE-CVE-2023-51443 |
| Alpine:v3.23 | freeswitch | 1.10.11-r0 | ALPINE-CVE-2023-51443 |
| Alpine:v3.24 | freeswitch | 1.10.11-r0 | ALPINE-CVE-2023-51443 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| signalwire | freeswitch | < 1.10.11 |
Weakness: CWE-703 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/signalwire/freeswitch/security/advisories/GHSA-39gv-hq72-j6m6 x_refsource_CONFIRM
- https://github.com/signalwire/freeswitch/commit/86cbda90b84ba186e508fbc7bfae469270a97d11 x_refsource_MISC
- http://packetstormsecurity.com/files/176393/FreeSWITCH-Denial-Of-Service.html
- http://packetstormsecurity.com/files/176311/FreeSWITCH-1.10.10-Denial-Of-Service.html
- http://seclists.org/fulldisclosure/2023/Dec/29