CVE-2025-20335

Cisco Desk Phone 9800 Series, IP Phone 7800 and 8800 Series, and Video Phone 8875 with SIP Firmware Information Arbitrary File Write Vulnerability

View on CVE.org

Published Sep 3, 2025 CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed

Description

A vulnerability in the directory permissions of Cisco Desk Phone 9800 Series, Cisco IP Phone 7800 and 8800 Series, and Cisco Video Phone 8875 could allow an unauthenticated, remote attacker to write arbitrary files on an affected device.

This vulnerability is due to a lack of proper authentication controls. An attacker could exploit this vulnerability by sending a crafted request to an affected device. A successful exploit could allow the attacker to perform arbitrary file writes to specific directories in the underlying operating system.
Note: To exploit this vulnerability, Web Access must be enabled on the phone. Web Access is disabled by default.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Cisco

Cisco Session Initiation Protocol (SIP) Software

unknown

Version	Status	Constraints
`12.1(1)SR1`	affected	—
`11.5(1)`	affected	—
`10.3(2)`	affected	—
`10.2(2)`	affected	—
`10.3(1)`	affected	—
`10.3(1)SR4`	affected	—
`11.0(1)`	affected	—
`10.4(1)SR2 3rd Party`	affected	—
`11.7(1)`	affected	—
`12.1(1)`	affected	—
`11.0(0.7) MPP`	affected	—
`9.3(4) 3rd Party`	affected	—
`12.5(1)SR2`	affected	—
`10.2(1)SR1`	affected	—
`9.3(4)SR3 3rd Party`	affected	—
`10.2(1)`	affected	—
`12.5(1)`	affected	—
`10.3(1)SR2`	affected	—
`11-0-1MSR1-1`	affected	—
`10.4(1) 3rd Party`	affected	—
`12.5(1)SR1`	affected	—
`11.5(1)SR1`	affected	—
`10.1(1)SR2`	affected	—
`12.0(1)SR2`	affected	—
`12.6(1)`	affected	—
`10.3(1.11) 3rd Party`	affected	—
`12.0(1)`	affected	—
`12.0(1)SR1`	affected	—
`9.3(3)`	affected	—
`12.5(1)SR3`	affected	—
`10.3(1)SR4b`	affected	—
`9.3(4)SR1 3rd Party`	affected	—
`10.3(1)SR5`	affected	—
`10.1(1.9)`	affected	—
`10.3(1.9) 3rd Party`	affected	—
`9.3(4)SR2 3rd Party`	affected	—
`10.3(1)SR1`	affected	—
`10.3(1)SR3`	affected	—
`10.1(1)SR1`	affected	—
`12.0(1)SR3`	affected	—
`12.6(1)SR1`	affected	—
`12.7(1)`	affected	—
`10.3(1)SR6`	affected	—
`12.8(1)`	affected	—
`12.7(1)SR1`	affected	—
`11.0(2)SR1`	affected	—
`11.0(4)`	affected	—
`11.0(2)`	affected	—
`11.0(4)SR3`	affected	—
`11.0(5)`	affected	—
`11.0(3)SR2`	affected	—
`11.0(3)SR4`	affected	—
`11.0(3)SR3`	affected	—
`11.0(2)SR2`	affected	—
`11.0(4)SR1`	affected	—
`11.0(5)SR3`	affected	—
`11.0(3)`	affected	—
`11.0(5)SR2`	affected	—
`11.0(3)SR6`	affected	—
`11.0(5)SR1`	affected	—
`11.0(4)SR2`	affected	—
`11.0(3)SR1`	affected	—
`11.0(3)SR5`	affected	—
`11.0(6)`	affected	—
`12.8(1)SR1`	affected	—
`12.8(1)SR2`	affected	—
`14.0(1)`	affected	—
`14.0(1)SR1`	affected	—
`11.0(6)SR1`	affected	—
`10.3(1)SR7`	affected	—
`14.0(1)SR2`	affected	—
`14.1(1)`	affected	—
`14.0(1)SR3`	affected	—
`11.0(6)SR2`	affected	—
`14.1(1)SR1`	affected	—
`14.1(1)SR2`	affected	—
`11.0(6)SR4`	affected	—
`14.2(1)`	affected	—
`14.2(1)SR1`	affected	—
`11.0(6)SR5`	affected	—
`14.1(1)SR3`	affected	—
`14.2(1)SR2`	affected	—
`3.1(1)`	affected	—
`3.0(1)`	affected	—
`2.3(1)`	affected	—
`2.3(1)SR1`	affected	—
`2.2(1)`	affected	—
`2.1(1)`	affected	—
`2.0(1)`	affected	—
`14.2(1)SR3`	affected	—
`3.1(1)SR1`	affected	—
`14.3(1)`	affected	—
`3.2(1)`	affected	—
`14.3(1)SR1`	affected	—
`14.2(1)SR4`	affected	—
`11.0(6)SR6`	affected	—

Configuration 1 [-]

AND

cpe:2.3:o:cisco:desk_phone_9841_firmware:*:*:*:*:*:*:*:*

cpe:2.3:h:cisco:desk_phone_9841:-:*:*:*:*:*:*:*

Configuration 2 [-]

AND

cpe:2.3:o:cisco:desk_phone_9851_firmware:*:*:*:*:*:*:*:*

cpe:2.3:h:cisco:desk_phone_9851:-:*:*:*:*:*:*:*

Configuration 3 [-]

AND

cpe:2.3:o:cisco:desk_phone_9861_firmware:*:*:*:*:*:*:*:*

cpe:2.3:h:cisco:desk_phone_9861:-:*:*:*:*:*:*:*

Configuration 4 [-]

AND

cpe:2.3:o:cisco:desk_phone_9871_firmware:*:*:*:*:*:*:*:*

cpe:2.3:h:cisco:desk_phone_9871:-:*:*:*:*:*:*:*

Configuration 5 [-]

AND

OR	cpe:2.3:o:cisco:ip_phone_7811_firmware::::::::
	cpe:2.3:o:cisco:ip_phone_7811_firmware:14.3\(1\):-::::::
	cpe:2.3:o:cisco:ip_phone_7811_firmware:14.3\(1\):sr1::::::

cpe:2.3:h:cisco:ip_phone_7811:-:*:*:*:*:*:*:*

Configuration 6 [-]

AND

OR	cpe:2.3:o:cisco:ip_phone_7821_firmware::::::::
	cpe:2.3:o:cisco:ip_phone_7821_firmware:14.3\(1\):-::::::
	cpe:2.3:o:cisco:ip_phone_7821_firmware:14.3\(1\):sr1::::::

cpe:2.3:h:cisco:ip_phone_7821:-:*:*:*:*:*:*:*

Configuration 7 [-]

AND

OR	cpe:2.3:o:cisco:ip_phone_7841_firmware::::::::
	cpe:2.3:o:cisco:ip_phone_7841_firmware:14.3\(1\):-::::::
	cpe:2.3:o:cisco:ip_phone_7841_firmware:14.3\(1\):sr1::::::

cpe:2.3:h:cisco:ip_phone_7841:-:*:*:*:*:*:*:*

Configuration 8 [-]

AND

OR	cpe:2.3:o:cisco:ip_phone_7861_firmware::::::::
	cpe:2.3:o:cisco:ip_phone_7861_firmware:14.3\(1\):-::::::
	cpe:2.3:o:cisco:ip_phone_7861_firmware:14.3\(1\):sr1::::::

cpe:2.3:h:cisco:ip_phone_7861:-:*:*:*:*:*:*:*

Configuration 9 [-]

AND

OR	cpe:2.3:o:cisco:ip_phone_8811_firmware::::::::
	cpe:2.3:o:cisco:ip_phone_8811_firmware:14.3\(1\):-::::::
	cpe:2.3:o:cisco:ip_phone_8811_firmware:14.3\(1\):sr1::::::

cpe:2.3:h:cisco:ip_phone_8811:-:*:*:*:*:*:*:*

Configuration 10 [-]

AND

OR	cpe:2.3:o:cisco:ip_phone_8841_firmware::::::::
	cpe:2.3:o:cisco:ip_phone_8841_firmware:14.3\(1\):-::::::
	cpe:2.3:o:cisco:ip_phone_8841_firmware:14.3\(1\):sr1::::::

cpe:2.3:h:cisco:ip_phone_8841:-:*:*:*:*:*:*:*

Configuration 11 [-]

AND

OR	cpe:2.3:o:cisco:ip_phone_8845_firmware::::::::
	cpe:2.3:o:cisco:ip_phone_8845_firmware:14.3\(1\):-::::::
	cpe:2.3:o:cisco:ip_phone_8845_firmware:14.3\(1\):sr1::::::

cpe:2.3:h:cisco:ip_phone_8845:-:*:*:*:*:*:*:*

Configuration 12 [-]

AND

OR	cpe:2.3:o:cisco:ip_phone_8851_firmware::::::::
	cpe:2.3:o:cisco:ip_phone_8851_firmware:14.3\(1\):-::::::
	cpe:2.3:o:cisco:ip_phone_8851_firmware:14.3\(1\):sr1::::::

cpe:2.3:h:cisco:ip_phone_8851:-:*:*:*:*:*:*:*

Configuration 13 [-]

AND

OR	cpe:2.3:o:cisco:ip_phone_8851nr_firmware::::::::
	cpe:2.3:o:cisco:ip_phone_8851nr_firmware:14.3\(1\):-::::::
	cpe:2.3:o:cisco:ip_phone_8851nr_firmware:14.3\(1\):sr1::::::

cpe:2.3:h:cisco:ip_phone_8851nr:-:*:*:*:*:*:*:*

Configuration 14 [-]

AND

OR	cpe:2.3:o:cisco:ip_phone_8861_firmware::::::::
	cpe:2.3:o:cisco:ip_phone_8861_firmware:14.3\(1\):-::::::
	cpe:2.3:o:cisco:ip_phone_8861_firmware:14.3\(1\):sr1::::::

cpe:2.3:h:cisco:ip_phone_8861:-:*:*:*:*:*:*:*

Configuration 15 [-]

AND

OR	cpe:2.3:o:cisco:ip_phone_8865_firmware::::::::
	cpe:2.3:o:cisco:ip_phone_8865_firmware:14.3\(1\):-::::::
	cpe:2.3:o:cisco:ip_phone_8865_firmware:14.3\(1\):sr1::::::

cpe:2.3:h:cisco:ip_phone_8865:-:*:*:*:*:*:*:*

Configuration 16 [-]

AND

OR	cpe:2.3:o:cisco:video_phone_8875_firmware::::::::
	cpe:2.3:o:cisco:video_phone_8875_firmware::::::::
	cpe:2.3:o:cisco:video_phone_8875_firmware:2.3\(1\):-::::::
	cpe:2.3:o:cisco:video_phone_8875_firmware:2.3\(1\):sr1::::::

cpe:2.3:h:cisco:video_phone_8875:-:*:*:*:*:*:*:*

Configuration 17 [-]

AND

OR	cpe:2.3:o:cisco:ip_phone_8821_firmware::::::::
	cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):-::::::
	cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):sr1::::::
	cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):sr2::::::
	cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):sr4::::::
	cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):sr5::::::
	cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):sr6::::::

cpe:2.3:h:cisco:ip_phone_8821:-:*:*:*:*:*:*:*

No data.

Vendor	Product	Versions
Cisco	Ip Phone 7800	—
Cisco	Ip Phone 8800	—
Cisco	Ip Phone 9800	—
Cisco	Session Initiation Protocol \(sip\) Firmware	—
Cisco	Video Phone 8875	—

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

Source	ID	Title
EUVD	EUVD-2025-26614	A vulnerability in the directory permissions of Cisco Desk Phone 9800 Series, Cisco IP Phone 7800 and 8800 Series, and Cisco Video Phone 8875 could allow an unauthenticated, remote attacker to write arbitrary files on an affected device. This vulnerability is due to a lack of proper authentication controls. An attacker could exploit this vulnerability by sending a crafted request to an affected device. A successful exploit could allow the attacker to perform arbitrary file writes to specific directories in the underlying operating system. Note: To exploit this vulnerability, Web Access must be enabled on the phone. Web Access is disabled by default.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact Low

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.353% probability within 30 days)

Exploitation none

Automatable yes

Technical Impact partial

References

Link	Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-phone-write-g3kcC5Df

History

Jan 5, 2026 3:00 PM First appearance in the feed. Affected versions updated. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Cisco desk Phone 9841 Cisco desk Phone 9841 Firmware Cisco desk Phone 9851 Cisco desk Phone 9851 Firmware Cisco desk Phone 9861 Cisco desk Phone 9861 Firmware Cisco desk Phone 9871 Cisco desk Phone 9871 Firmware Cisco ip Phone 7811 Cisco ip Phone 7811 Firmware Cisco ip Phone 7821 Cisco ip Phone 7821 Firmware Cisco ip Phone 7841 Cisco ip Phone 7841 Firmware Cisco ip Phone 7861 Cisco ip Phone 7861 Firmware Cisco ip Phone 8811 Cisco ip Phone 8811 Firmware Cisco ip Phone 8821 Cisco ip Phone 8821 Firmware Cisco ip Phone 8841 Cisco ip Phone 8841 Firmware Cisco ip Phone 8845 Cisco ip Phone 8845 Firmware Cisco ip Phone 8851 Cisco ip Phone 8851 Firmware Cisco ip Phone 8851nr Cisco ip Phone 8851nr Firmware Cisco ip Phone 8861 Cisco ip Phone 8861 Firmware Cisco ip Phone 8865 Cisco ip Phone 8865 Firmware Cisco video Phone 8875 Firmware
CPEs		cpe:2.3:h:cisco:desk_phone_9841:-:::::::* cpe:2.3:h:cisco:desk_phone_9851:-:::::::* cpe:2.3:h:cisco:desk_phone_9861:-:::::::* cpe:2.3:h:cisco:desk_phone_9871:-:::::::* cpe:2.3:h:cisco:ip_phone_7811:-:::::::* cpe:2.3:h:cisco:ip_phone_7821:-:::::::* cpe:2.3:h:cisco:ip_phone_7841:-:::::::* cpe:2.3:h:cisco:ip_phone_7861:-:::::::* cpe:2.3:h:cisco:ip_phone_8811:-:::::::* cpe:2.3:h:cisco:ip_phone_8821:-:::::::* cpe:2.3:h:cisco:ip_phone_8841:-:::::::* cpe:2.3:h:cisco:ip_phone_8845:-:::::::* cpe:2.3:h:cisco:ip_phone_8851:-:::::::* cpe:2.3:h:cisco:ip_phone_8851nr:-:::::::* cpe:2.3:h:cisco:ip_phone_8861:-:::::::* cpe:2.3:h:cisco:ip_phone_8865:-:::::::* cpe:2.3:h:cisco:video_phone_8875:-:::::::* cpe:2.3:o:cisco:desk_phone_9841_firmware:::::::: cpe:2.3:o:cisco:desk_phone_9851_firmware:::::::: cpe:2.3:o:cisco:desk_phone_9861_firmware:::::::: cpe:2.3:o:cisco:desk_phone_9871_firmware:::::::: cpe:2.3:o:cisco:ip_phone_7811_firmware:::::::: cpe:2.3:o:cisco:ip_phone_7811_firmware:14.3\(1\):-:::::: cpe:2.3:o:cisco:ip_phone_7811_firmware:14.3\(1\):sr1:::::: cpe:2.3:o:cisco:ip_phone_7821_firmware:::::::: cpe:2.3:o:cisco:ip_phone_7821_firmware:14.3\(1\):-:::::: cpe:2.3:o:cisco:ip_phone_7821_firmware:14.3\(1\):sr1:::::: cpe:2.3:o:cisco:ip_phone_7841_firmware:::::::: cpe:2.3:o:cisco:ip_phone_7841_firmware:14.3\(1\):-:::::: cpe:2.3:o:cisco:ip_phone_7841_firmware:14.3\(1\):sr1:::::: cpe:2.3:o:cisco:ip_phone_7861_firmware:::::::: cpe:2.3:o:cisco:ip_phone_7861_firmware:14.3\(1\):-:::::: cpe:2.3:o:cisco:ip_phone_7861_firmware:14.3\(1\):sr1:::::: cpe:2.3:o:cisco:ip_phone_8811_firmware:::::::: cpe:2.3:o:cisco:ip_phone_8811_firmware:14.3\(1\):-:::::: cpe:2.3:o:cisco:ip_phone_8811_firmware:14.3\(1\):sr1:::::: cpe:2.3:o:cisco:ip_phone_8821_firmware:::::::: cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):-:::::: cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):sr1:::::: cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):sr2:::::: cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):sr4:::::: cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):sr5:::::: cpe:2.3:o:cisco:ip_phone_8821_firmware:11.0\(6\):sr6:::::: cpe:2.3:o:cisco:ip_phone_8841_firmware:::::::: cpe:2.3:o:cisco:ip_phone_8841_firmware:14.3\(1\):-:::::: cpe:2.3:o:cisco:ip_phone_8841_firmware:14.3\(1\):sr1:::::: cpe:2.3:o:cisco:ip_phone_8845_firmware:::::::: cpe:2.3:o:cisco:ip_phone_8845_firmware:14.3\(1\):-:::::: cpe:2.3:o:cisco:ip_phone_8845_firmware:14.3\(1\):sr1:::::: cpe:2.3:o:cisco:ip_phone_8851_firmware:::::::: cpe:2.3:o:cisco:ip_phone_8851_firmware:14.3\(1\):-:::::: cpe:2.3:o:cisco:ip_phone_8851_firmware:14.3\(1\):sr1:::::: cpe:2.3:o:cisco:ip_phone_8851nr_firmware:::::::: cpe:2.3:o:cisco:ip_phone_8851nr_firmware:14.3\(1\):-:::::: cpe:2.3:o:cisco:ip_phone_8851nr_firmware:14.3\(1\):sr1:::::: cpe:2.3:o:cisco:ip_phone_8861_firmware:::::::: cpe:2.3:o:cisco:ip_phone_8861_firmware:14.3\(1\):-:::::: cpe:2.3:o:cisco:ip_phone_8861_firmware:14.3\(1\):sr1:::::: cpe:2.3:o:cisco:ip_phone_8865_firmware:::::::: cpe:2.3:o:cisco:ip_phone_8865_firmware:14.3\(1\):-:::::: cpe:2.3:o:cisco:ip_phone_8865_firmware:14.3\(1\):sr1:::::: cpe:2.3:o:cisco:video_phone_8875_firmware:::::::: cpe:2.3:o:cisco:video_phone_8875_firmware:2.3\(1\):-:::::: cpe:2.3:o:cisco:video_phone_8875_firmware:2.3\(1\):sr1::::::
Vendors & Products		Cisco desk Phone 9841 Cisco desk Phone 9841 Firmware Cisco desk Phone 9851 Cisco desk Phone 9851 Firmware Cisco desk Phone 9861 Cisco desk Phone 9861 Firmware Cisco desk Phone 9871 Cisco desk Phone 9871 Firmware Cisco ip Phone 7811 Cisco ip Phone 7811 Firmware Cisco ip Phone 7821 Cisco ip Phone 7821 Firmware Cisco ip Phone 7841 Cisco ip Phone 7841 Firmware Cisco ip Phone 7861 Cisco ip Phone 7861 Firmware Cisco ip Phone 8811 Cisco ip Phone 8811 Firmware Cisco ip Phone 8821 Cisco ip Phone 8821 Firmware Cisco ip Phone 8841 Cisco ip Phone 8841 Firmware Cisco ip Phone 8845 Cisco ip Phone 8845 Firmware Cisco ip Phone 8851 Cisco ip Phone 8851 Firmware Cisco ip Phone 8851nr Cisco ip Phone 8851nr Firmware Cisco ip Phone 8861 Cisco ip Phone 8861 Firmware Cisco ip Phone 8865 Cisco ip Phone 8865 Firmware Cisco video Phone 8875 Firmware

Sep 4, 2025 1:15 PM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Cisco Cisco ip Phone 7800 Cisco ip Phone 8800 Cisco ip Phone 9800 Cisco session Initiation Protocol \(sip\) Firmware Cisco video Phone 8875
Vendors & Products		Cisco Cisco ip Phone 7800 Cisco ip Phone 8800 Cisco ip Phone 9800 Cisco session Initiation Protocol \(sip\) Firmware Cisco video Phone 8875

Sep 3, 2025 6:15 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Sep 3, 2025 5:45 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		A vulnerability in the directory permissions of Cisco Desk Phone 9800 Series, Cisco IP Phone 7800 and 8800 Series, and Cisco Video Phone 8875 could allow an unauthenticated, remote attacker to write arbitrary files on an affected device. This vulnerability is due to a lack of proper authentication controls. An attacker could exploit this vulnerability by sending a crafted request to an affected device. A successful exploit could allow the attacker to perform arbitrary file writes to specific directories in the underlying operating system. Note: To exploit this vulnerability, Web Access must be enabled on the phone. Web Access is disabled by default.
Title		Cisco Desk Phone 9800 Series, IP Phone 7800 and 8800 Series, and Video Phone 8875 with SIP Firmware Information Arbitrary File Write Vulnerability
Weaknesses		CWE-284
References		https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-phone-write-g3kcC5Df
Metrics		cvssV3_1 `{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}`

Subscriptions

Cisco Desk Phone 9841 Desk Phone 9841 Firmware Desk Phone 9851 Desk Phone 9851 Firmware Desk Phone 9861 Desk Phone 9861 Firmware Desk Phone 9871 Desk Phone 9871 Firmware Ip Phone 7800 Ip Phone 7811 Ip Phone 7811 Firmware Ip Phone 7821 Ip Phone 7821 Firmware Ip Phone 7841 Ip Phone 7841 Firmware Ip Phone 7861 Ip Phone 7861 Firmware Ip Phone 8800 Ip Phone 8811 Ip Phone 8811 Firmware Ip Phone 8821 Ip Phone 8821 Firmware Ip Phone 8841 Ip Phone 8841 Firmware Ip Phone 8845 Ip Phone 8845 Firmware Ip Phone 8851 Ip Phone 8851 Firmware Ip Phone 8851nr Ip Phone 8851nr Firmware Ip Phone 8861 Ip Phone 8861 Firmware Ip Phone 8865 Ip Phone 8865 Firmware Ip Phone 9800 Session Initiation Protocol \(sip\) Firmware Video Phone 8875 Video Phone 8875 Firmware

Weaknesses