CVE-2019-1683 [High] | Security Vulnerability in Spa112 Firmware

A vulnerability in the certificate handling component of the Cisco SPA112, SPA525, and SPA5X5 Series IP Phones could allow an unauthenticated, remote attacker to listen to or control some aspects of a Transport Level Security (TLS)-encrypted Session Initiation Protocol (SIP) conversation. The vulnerability is due to the improper validation of server certificates. An attacker could exploit this vulnerability by crafting a malicious server certificate to present to the client. An exploit could allow an attacker to eavesdrop on TLS-encrypted traffic and potentially route or redirect calls initiated by an affected device. Affected software include version 7.6.2 of the Cisco Small Business SPA525 Series IP Phones and Cisco Small Business SPA5X5 Series IP Phones and version 1.4.2 of the Cisco Small Business SPA500 Series IP Phones and Cisco Small Business SPA112 Series IP Phones.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.16%	0.87%	+0.72%
2	2025-03-17	0.13%	0.16%	+0.03%
3	2025-02-04	—	0.13%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.16%

0.87%

+0.72%

2025-03-17

0.13%

0.16%

+0.03%

2025-02-04

—

0.13%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.4	3.1	HIGH	`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N` 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:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. 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:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:N) Service keeps running; no real outage angle.	2.2	5.2	[email protected]
6.5	3.0	MEDIUM	`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N` 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:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. 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:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:N) Service keeps running; no real outage angle.	2.2	4.2	[email protected]
5.8	2.0	MEDIUM	`AV:N/AC:M/Au:N/C:P/I:P/A:N` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:N) No authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:N) No availability impact.	8.6	4.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.4

3.1

HIGH

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N 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:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N): Service keeps running; no real outage angle.

2.2

5.2

[email protected]

6.5

3.0

MEDIUM

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N 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:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
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:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N): Service keeps running; no real outage angle.

2.2

4.2

[email protected]

5.8

2.0

MEDIUM

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

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:N): No availability impact.

8.6

4.9

[email protected]

Affected software / configurations for CVE-2019-1683

Vendor	Product	Version	Raw CPE
cisco	spa112_firmware	1.4.2	cpe:2.3:o:cisco:spa112_firmware:1.4.2:::::::*
cisco	spa525_firmware	7.6.2	cpe:2.3:o:cisco:spa525_firmware:7.6.2:::::::*
cisco	spa5x5_firmware	7.6.2	cpe:2.3:o:cisco:spa5x5_firmware:7.6.2:::::::*
cisco	spa500_firmware	1.4.2	cpe:2.3:o:cisco:spa500_firmware:1.4.2:::::::*
cisco	spa500s_firmware	1.4.2	cpe:2.3:o:cisco:spa500s_firmware:1.4.2:::::::*
cisco	spa500ds_firmware	1.4.2	cpe:2.3:o:cisco:spa500ds_firmware:1.4.2:::::::*
cisco	spa501g_firmware	1.4.2	cpe:2.3:o:cisco:spa501g_firmware:1.4.2:::::::*
cisco	spa502g_firmware	1.4.2	cpe:2.3:o:cisco:spa502g_firmware:1.4.2:::::::*
cisco	spa504g_firmware	1.4.2	cpe:2.3:o:cisco:spa504g_firmware:1.4.2:::::::*
cisco	spa508g_firmware	1.4.2	cpe:2.3:o:cisco:spa508g_firmware:1.4.2:::::::*
cisco	spa509g_firmware	1.4.2	cpe:2.3:o:cisco:spa509g_firmware:1.4.2:::::::*
cisco	spa512g_firmware	1.4.2	cpe:2.3:o:cisco:spa512g_firmware:1.4.2:::::::*
cisco	spa514g_firmware	1.4.2	cpe:2.3:o:cisco:spa514g_firmware:1.4.2:::::::*
cisco	spa525g_firmware	1.4.2	cpe:2.3:o:cisco:spa525g_firmware:1.4.2:::::::*

References for CVE-2019-1683

URL	Tags
http://www.securityfocus.com/bid/107111	Broken Link Third Party Advisory VDB Entry
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190220-ipphone-certs	Vendor Advisory

URL

CVE-2019-1683 | Cisco SPA112, SPA525, and SPA5x5 Series IP Phones Certificate Validation Vulnerability

Exploit prediction scoring system (EPSS) score for CVE-2019-1683

Common vulnerability scoring system (CVSS) metrics for CVE-2019-1683

Weakness enumeration for CVE-2019-1683

Affected software / configurations for CVE-2019-1683

References for CVE-2019-1683