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Vulnerability record · CVE-2020-27507 · published 15 March 2023

CVE-2020-27507: Kamailio classic buffer overflow vulnerability

Kamailio · Kamailio

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.

9.8 CVSS 3.1 Critical EPSS 1.2% · top 33.7% CWE-120 · Classic buffer overflow
9.8CVSS 3.1 base score
1.2%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
6References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

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.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/kamailio/kamailio/commit/ada3701d22b1fd579f06b4f54fa695fa988e685f Patch
https://github.com/kamailio/kamailio/issues/2503 ExploitIssue Tracking
https://lists.debian.org/debian-lts-announce/2023/05/msg00030.html
https://github.com/kamailio/kamailio/commit/ada3701d22b1fd579f06b4f54fa695fa988e685f Patch
https://github.com/kamailio/kamailio/issues/2503 ExploitIssue Tracking
https://lists.debian.org/debian-lts-announce/2023/05/msg00030.html

Track CVE-2020-27507 inside VULONE

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2018-16657Debian linux null pointer dereference vulnerabilityIn Kamailio before 5.0.7 and 5.1.x before 5.1.4, a crafted SIP message with an invalid Via header causes a segmentation fault and crashes Kamailio. T…EPSS 3.6%9.8CVE-2018-14767Debian linux improper input validation vulnerabilityIn Kamailio before 5.0.7 and 5.1.x before 5.1.4, a crafted SIP message with a double "To" header and an empty "To" tag causes a segmentation fault an…EPSS 29%9.8CVE-2018-8828Kamailio out-of-bounds write vulnerabilityA Buffer Overflow issue was discovered in Kamailio before 4.4.7, 5.0.x before 5.0.6, and 5.1.x before 5.1.2. A specially crafted REGISTER message wit…EPSS 30%9.8CVE-2013-7426Kamailio unrestricted file upload vulnerabilityInsecure Temporary file vulnerability in /tmp/kamailio_fifo in kamailio 4.0.1.EPSS 2.2%9.8CVE-2016-2385Debian linux memory buffer overflow vulnerabilityHeap-based buffer overflow in the encode_msg function in encode_msg.c in the SEAS module in Kamailio (formerly OpenSER and SER) before 4.3.5 allows r…EPSS 31%7.8CVE-2015-1590Kamailio permissions and access controls vulnerabilityThe kamcmd administrative utility and default configuration in kamailio before 4.3.0 use /tmp/kamailio_ctl.EPSS 0.43%7.8CVE-2015-1591Kamailio permissions and access controls vulnerabilityThe kamailio build in kamailio before 4.2.0-2 process allows local users to gain privileges.EPSS 0.39%7.5CVE-2026-52022Kamailio uncontrolled resource consumption vulnerabilityAn issue in kamailio v.6.1.1 and before allows a remote attacker to cause a denial of service via the IMS P-CSCF registration handling componentsEPSS 0.58%

Source: NIST National Vulnerability Database (record CVE-2020-27507), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.