CVE-2013-3722Network attack vector

Unauthenticated service hang via stalled registrar lookup iterator

Published Feb 17, 2020 · Updated Aug 6, 2024

Denial of service in OpenSIPS before 1.10 allows remote attackers to hang the SIP service by triggering registrar lookup processing. The lookup function in modules/registrar/lookup.c fails to advance its contact-list iterator while handling a temporary GRUU entry, so the same entry is processed indefinitely. A network-reachable SIP request that exercises registrar lookup against the affected temporary-GRUU state consumes a worker in an infinite loop, interrupting call-routing availability.

CVSS severity7.5
High
EPSS probability1.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in OpenSIPS before 1.10 allows remote attackers to hang the SIP service by triggering registrar lookup processing. The lookup function in modules/registrar/lookup.c fails to advance its contact-list iterator while handling a temporary GRUU entry, so the same entry is processed indefinitely. A network-reachable SIP request that exercises registrar lookup against the affected temporary-GRUU state consumes a worker in an infinite loop, interrupting call-routing availability.

The record

CVE
CVE-2013-3722
Published
Feb 17, 2020
Updated
Aug 6, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-835, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 17, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 6, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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