HOMEVULNERABILITIESCVE-2020-28361
MEDIUM

CVE-2020-28361

CWE-444Published: November 18, 2020· Updated: Jun 17, 2026

5.4
CVSS v3.1

Official Description

Kamailio before 5.4.0, as used in Sip Express Router (SER) in Sippy Softswitch 4.5 through 5.2 and other products, allows a bypass of a header-removal protection mechanism via whitespace characters. This occurs in the remove_hf function in the Kamailio textops module. Particular use of remove_hf in Sippy Softswitch may allow skilled attacker having a valid credential in the system to disrupt internal call start/duration accounting mechanisms leading potentially to a loss of revenue.

NVD Source

Technical Analysis

CVE-2020-28361 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.Low
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityLow
IntegrityLow
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Affected Vendors & Products

kamailio1 product(s)
kamailio
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://packetstormsecurity.com/files/159030/Kamailio-5.4.0-Header-Smuggling.html
ADVISORYhttps://packetstormsecurity.com/files/159030/Kamailio-5.4.0-Header-Smuggling.html

All References (4)

→
https://packetstormsecurity.com/files/159030/Kamailio-5.4.0-Header-Smuggling.htmlExploit · Third Party Advisory · VDB Entry
→
https://support.sippysoft.com/support/discussions/topics/3000179616Permissions Required
→
https://packetstormsecurity.com/files/159030/Kamailio-5.4.0-Header-Smuggling.htmlExploit · Third Party Advisory · VDB Entry
→
https://support.sippysoft.com/support/discussions/topics/3000179616Permissions Required

Quick Facts

CVE IDCVE-2020-28361
CVSS Score5.4 / 10
SeverityMEDIUM
WeaknessCWE-444
CISA KEVNo
Affected1 vendor(s)
PublishedNov 18, 2020

Related CVEs (CWE-444)

CVE-2018-3907
10.0
CVE-2025-1867
10.0
CVE-2025-55315
9.9
CVE-2015-5740
9.8
CVE-2021-45468
9.8
CVE-2015-5739
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2020-28361 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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