OpenSIPS: OOB Read in Multipart Body Boundary Parsing
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
OpenSIPS is a Session Initiation Protocol (SIP) server implementation. In versions prior to 3.6.6 and 4.0.0-rc1, the find_line_delimiter() function in the multipart body parser performs an out-of-bounds read via strncmp() when searching for MIME boundary delimiters. After finding a -- pattern near the end of the body, the function compares delimiter.len bytes (typically 20-70) starting from a position at or past the logical end of the body buffer, reading past the body boundary. The bug triggers when a SIP message has Content-Type: multipart/mixed with a boundary parameter and its body contains -- within two to three bytes of the body's end without being followed by the actual boundary delimiter. This issue has been fixed in versions 3.6.6 and 4.0.0-rc1.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA opensips (OpenSIPS) Fixed in 3.6.6, 4.0.0-rc1
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2026-45705
References
More OpenSIPS vulnerabilities
- TI-2026-33290 OpenSIPS: Stack Buffer Overflow in sip_to_json() Header Name Copy CVSS 3.1CRITICAL 9.8
- TI-2026-33289 OpenSIPS: Global Buffer Overflow in construct_uri CVSS 3.1CRITICAL 9.1
- TI-2026-32940 OpenSIPS: Buffer Overflow in Base64 Encode Transformation CVSS 3.1CRITICAL 9.1
- TI-2026-34055 OpenSIPS: Denial of Service in SDP bandwidth parsing via QoS SDP cloning CVSS 4.0HIGH 8.7
- TI-2026-33544 OpenSIPS: Denial of Service in watcherinfo XML generation from oversized watcher URI CVSS 4.0HIGH 8.7
- TI-2026-32931 OpenSIPS: Denial of service in presence.handle_publish() from unchecked Content-Type state CVSS 4.0HIGH 8.7
Sources
- CVE-2026-45705 · CVE Program
- CVE-2026-45705 · NVD
- FIRST EPSS
- CVE-2026-45705 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences