CVE-2009-5140Public exploitNetwork attack vector

Hashed credential disclosure via forged SIP challenge

Published Feb 12, 2020 · Updated Aug 7, 2024

SIP digest leakage in the Linksys SPA2102 phone adapter allows remote attackers to obtain hashed credentials through a forged challenge. After a call ends, the adapter accepts an attacker-controlled SIP 407 response to its BYE request and returns a second BYE containing the digest response. The attacker must know a callable extension and a user must answer and hang up; the leaked response enables offline password cracking and subsequent account access.

CVSS severity8.8
High
EPSS probability1.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SIP digest leakage in the Linksys SPA2102 phone adapter allows remote attackers to obtain hashed credentials through a forged challenge. After a call ends, the adapter accepts an attacker-controlled SIP 407 response to its BYE request and returns a second BYE containing the digest response. The attacker must know a callable extension and a user must answer and hang up; the leaked response enables offline password cracking and subsequent account access.

The record

CVE
CVE-2009-5140
Published
Feb 12, 2020
Updated
Aug 7, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-307, T1110.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 12, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 7, 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

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
4.3NIST NVDAV:N/AC:M/Au:N/C:P/I:N/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitPublished

Weakness, pattern, technique

CWE-307Improper Restriction of Excessive Authentication Attempts
T1110.002Password Cracking

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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