The Kamailio SIP before 5.5.0 server mishandles INVITE requests with duplicated fields and overlength tag, leading to a buffer overflow that crashes the server or possibly have unspecified other impact.
CVE-2020-27507
CRITICALNVD 9.89.8—Elevated
EchelonGraph scoreMEDIUM confidence
Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2023-03-15. NVD baseline CVSS 9.8; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: Elevated riskExposed: 0
A fix is available — apply it.
- CVSS v3
- 9.8
- EG Score
- 9.8(medium)
- EG Risk
- 75(Attend)EG Risk 75/100SSVC: Attend
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity98% × 45%Exploitation40% × 40%Automatability100% × 15%Action: Remediate soon — notable exploitation risk. - EPSS PROB
- 1%
- EPSS %ILE
- 66%
- KEV
- Not listed
Published
March 15, 2023
Last Modified
February 27, 2025
References (6)
- cve@mitrehttps://github.com/kamailio/kamailio/commit/ada3701d22b1fd579f06b4f54fa695fa988e685f
- cve@mitrehttps://github.com/kamailio/kamailio/issues/2503
- cve@mitrehttps://lists.debian.org/debian-lts-announce/2023/05/msg00030.html
- af854a3a-2127-422b-91ae-364da2661108https://github.com/kamailio/kamailio/commit/ada3701d22b1fd579f06b4f54fa695fa988e685f
- af854a3a-2127-422b-91ae-364da2661108https://github.com/kamailio/kamailio/issues/2503
- af854a3a-2127-422b-91ae-364da2661108https://lists.debian.org/debian-lts-announce/2023/05/msg00030.html
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Frequently asked(5)
What is CVE-2020-27507?
CVE-2020-27507 is a critical vulnerability published on March 15, 2023. The Kamailio SIP before 5.5.0 server mishandles INVITE requests with duplicated fields and overlength tag, leading to a buffer overflow that crashes the server or possibly have unspecified other impact.
When was CVE-2020-27507 disclosed?
CVE-2020-27507 was first published in the National Vulnerability Database on March 15, 2023, with the most recent update on February 27, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-27507 actively exploited?
CVE-2020-27507 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 33.8% of all scored CVEs.
What is the CVSS score of CVE-2020-27507?
CVE-2020-27507 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2020-27507?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-27507, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2020-27507
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