Server crash via unchecked backward SDP scan
Published Mar 15, 2023 · Updated Feb 25, 2025
Denial of service in the sipmsgops module in OpenSIPS before 3.1.8 and 3.2.0 through 3.2.4 allows remote attackers to crash the server. The stream_process function walks backward while trimming spaces without first ensuring that its pointer remains inside the SDP buffer, so repeated malformed SDP processing reads before the buffer boundary. Exploitation requires a configuration that invokes affected sipmsgops processing, such as codec_delete_except_re, and interrupts the SIP service.
Summary
What happened
Denial of service in the sipmsgops module in OpenSIPS before 3.1.8 and 3.2.0 through 3.2.4 allows remote attackers to crash the server. The stream_process function walks backward while trimming spaces without first ensuring that its pointer remains inside the SDP buffer, so repeated malformed SDP processing reads before the buffer boundary. Exploitation requires a configuration that invokes affected sipmsgops processing, such as codec_delete_except_re, and interrupts the SIP service.
The record
- CVE
- CVE-2023-27596
- Published
- Mar 15, 2023
- Updated
- Feb 25, 2025
- Vendor
- OpenSIPS
- Product
- OpenSIPS
- Classifications
- CWE-770, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 15, 2023CVE publishedPublication date reported by the CVE source.
- Feb 25, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 3.1.8
- Affected versionversion=>= 3.2.0, < 3.2.5
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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