Multiple vulnerabilities in KDDI HGW-BL1500HM

1) Stored cross-site scripting

EUVDB-ID: #VU105864

Risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-27567

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Exploit availability: No

Description

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data in the NickName registration screen. A remote user can inject and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

HGW-BL1500HM: 002.002.003

CPE2.3

External links

https://jvn.jp/en/jp/JVN04278547/index.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

2) Stored cross-site scripting

EUVDB-ID: #VU105865

Risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-27574

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Exploit availability: No

Description

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data in the USB storage file-sharing function. A remote user can inject and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

HGW-BL1500HM: 002.002.003

CPE2.3

External links

https://jvn.jp/en/jp/JVN04278547/index.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

3) Path traversal

EUVDB-ID: #VU105866

Risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-27716

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences in the file/folder listing process of the USB storage file-sharing function. A remote user can send a specially crafted HTTP request and read arbitrary files on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

HGW-BL1500HM: 002.002.003

CPE2.3

External links

https://jvn.jp/en/jp/JVN04278547/index.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

4) Path traversal

EUVDB-ID: #VU105867

Risk: Medium

CVSSv4.0: 6.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-27718

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences in the file upload process of the USB storage file-sharing function. A remote user can send a specially crafted HTTP request and read arbitrary files on the system, leading to arbitrary code execution.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

HGW-BL1500HM: 002.002.003

CPE2.3

External links

https://jvn.jp/en/jp/JVN04278547/index.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

5) Path traversal

EUVDB-ID: #VU105868

Risk: Low

CVSSv4.0: 0.4 [CVSS:4.0/AV:P/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2025-27726

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Exploit availability: No

Description

The vulnerability allows a local attacker to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences in the file download process of the USB storage file-sharing function. An authenticated attacker with physical access can send a specially crafted HTTP request and read arbitrary files on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

HGW-BL1500HM: 002.002.003

CPE2.3

External links

https://jvn.jp/en/jp/JVN04278547/index.html

Q & A

Can this vulnerability be exploited remotely?

No. The attacker should have physical access to the system in order to successfully exploit this vulnerability.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

6) Path traversal

EUVDB-ID: #VU105869

Risk: Medium

CVSSv4.0: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-27932

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences in the file deletion process of the USB storage file-sharing function. A remote user can send a specially crafted HTTP request and delete arbitrary files on the system, leading to denial of service (DoS) condition.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

HGW-BL1500HM: 002.002.003

CPE2.3

External links

https://jvn.jp/en/jp/JVN04278547/index.html

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected device in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.

Risk	Medium
Patch available	YES
Number of vulnerabilities	6
CVE-ID	CVE-2025-27567 CVE-2025-27574 CVE-2025-27716 CVE-2025-27718 CVE-2025-27726 CVE-2025-27932
CWE-ID	CWE-79 CWE-22
Exploitation vector	Network
Public exploit	N/A
Vulnerable software	HGW-BL1500HM Hardware solutions / Routers & switches, VoIP, GSM, etc
Vendor	KDDI CORPORATION