What is the CVSS score of CVE-2021-41105?

CVE-2021-41105 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 2.4%.

Is there a public PoC exploit available for CVE-2021-41105?

Yes, a public proof-of-concept exploit is available for CVE-2021-41105. Prioritise patching immediately. EPSS: 2.4%.

Freeswitch CVE-2021-41105

HIGH

Improper Input Validation (CWE-20)

2021-10-25 security-advisories@github.com

Microsoft Denial Of Service Freeswitch

7.5

CVSS 3.1 · Vendor: github

Severity by source

Vendor (github) PRIMARY

7.5 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Primary rating from Vendor (github) · only source for this CVE.

CVSS VectorVendor: github

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

CVE Published

Oct 25, 2021 - 22:15 cve.org

HIGH 7.5

DescriptionCVE.org

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. When handling SRTP calls, FreeSWITCH prior to version 1.10.7 is susceptible to a DoS where calls can be terminated by remote attackers. This attack can be done continuously, thus denying encrypted calls during the attack. When a media port that is handling SRTP traffic is flooded with a specially crafted SRTP packet, the call is terminated leading to denial of service. This issue was reproduced when using the SDES key exchange mechanism in a SIP environment as well as when using the DTLS key exchange mechanism in a WebRTC environment. The call disconnection occurs due to line 6331 in the source file switch_rtp.c, which disconnects the call when the total number of SRTP errors reach a hard-coded threshold (100). By abusing this vulnerability, an attacker is able to disconnect any ongoing calls that are using SRTP. The attack does not require authentication or any special foothold in the caller's or the callee's network. This issue is patched in version 1.10.7.

AnalysisAI

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. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified under CWE-20. 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. When handling SRTP calls, FreeSWITCH prior to version 1.10.7 is susceptible to a DoS where calls can be terminated by remote attackers. This attack can be done continuously, thus denying encrypted calls during the attack. When a media port that is handling SRTP traffic is flooded with a specially crafted SRTP packet, the call is terminated leading to denial of service. This issue was reproduced when using the SDES key exchange mechanism in a SIP environment as well as when using the DTLS key exchange mechanism in a WebRTC environment. The call disconnection occurs due to line 6331 in the source file switch_rtp.c, which disconnects the call when the total number of SRTP errors reach a hard-coded threshold (100). By abusing this vulnerability, an attacker is able to disconnect any ongoing calls that are using SRTP. The attack does not require authentication or any special foothold in the caller's or the callee's network. This issue is patched in version 1.10.7. Affected products include: Freeswitch. Version information: version 1.10.7.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.