CVE-2017-12260 [High] | Memory Corruption in Spa 501g Firmware

A vulnerability in the implementation of Session Initiation Protocol (SIP) functionality in Cisco Small Business SPA50x, SPA51x, and SPA52x Series IP Phones could allow an unauthenticated, remote attacker to cause an affected device to become unresponsive, resulting in a denial of service (DoS) condition. The vulnerability is due to the improper handling of SIP request messages by an affected device. An attacker could exploit this vulnerability by using formatted specifiers in a SIP payload that is sent to an affected device. A successful exploit could allow the attacker to cause the affected device to become unresponsive, resulting in a DoS condition that persists until the device is restarted manually. This vulnerability affects Cisco Small Business SPA50x, SPA51x, and SPA52x Series IP Phones that are running firmware release 7.6.2SR1 or earlier. Cisco Bug IDs: CSCvc63986.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	1.41%	2.30%	+0.89%
2	2025-03-30	1.85%	1.41%	-0.45%
3	2025-03-29	—	1.85%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

1.41%

2.30%

+0.89%

2025-03-30

1.85%

1.41%

-0.45%

2025-03-29

—

1.85%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.5	3.0	HIGH	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	3.6	[email protected]
5.0	2.0	MEDIUM	`AV:N/AC:L/Au:N/C:N/I:N/A:P` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:N) No confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:P) Partial availability impact.	10.0	2.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.5

3.0

HIGH

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

3.6

[email protected]

5.0

2.0

MEDIUM

AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:N): No confidentiality impact.
Integrity impact (I:N): No integrity impact.
Availability impact (A:P): Partial availability impact.

10.0

2.9

[email protected]

Affected software / configurations for CVE-2017-12260

Vendor	Product	Version	Raw CPE
cisco	spa_501g_firmware	<= 7.6.2	cpe:2.3:o:cisco:spa_501g_firmware::sr1::::::*
cisco	spa_502g_firmware	<= 7.6.2	cpe:2.3:o:cisco:spa_502g_firmware::sr1::::::*
cisco	spa_504g_firmware	<= 7.6.2	cpe:2.3:o:cisco:spa_504g_firmware::sr1::::::*
cisco	spa_508g_firmware	<= 7.6.2	cpe:2.3:o:cisco:spa_508g_firmware::sr1::::::*
cisco	spa_509g_firmware	<= 7.6.2	cpe:2.3:o:cisco:spa_509g_firmware::sr1::::::*
cisco	spa_512g_firmware	<= 7.6.2	cpe:2.3:o:cisco:spa_512g_firmware::sr1::::::*
cisco	spa_514g_firmware	<= 7.6.2	cpe:2.3:o:cisco:spa_514g_firmware::sr1::::::*
cisco	spa_525g_firmware	<= 7.6.2	cpe:2.3:o:cisco:spa_525g_firmware::sr1::::::*

References for CVE-2017-12260

URL	Tags
http://www.securityfocus.com/bid/101495	Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1039616	Third Party Advisory VDB Entry
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20171018-sip1	Vendor Advisory

URL

CVE-2017-12260

Exploit prediction scoring system (EPSS) score for CVE-2017-12260

Common vulnerability scoring system (CVSS) metrics for CVE-2017-12260

Weakness enumeration for CVE-2017-12260

Affected software / configurations for CVE-2017-12260

References for CVE-2017-12260