Denial of service in PHP

1) Resource exhaustion

EUVDB-ID: #VU10338

Risk: Low

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2017-9119

CWE-ID: CWE-400 - Resource exhaustion

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform denial of service (DoS) attack.

The vulnerability exists due to insufficient input validation in i_zval_ptr_dtor function in Zend/zend_variables.h when processing array data structures. A remote attacker can consume all available resources on the system and trigger application crash.

Mitigation

Update to version 5.6.31, 7.0.20 or 7.1.6.

Vulnerable software versions

PHP: 5.5.0 - 7.1.5

CPE2.3

• cpe:2.3:a:php_group:php:5.5.38:*:*:*:*:*:*:*
• cpe:2.3:a:php_group:php:5.6.30:*:*:*:*:*:*:*
• cpe:2.3:a:php_group:php:7.0.19:*:*:*:*:*:*:*
• cpe:2.3:a:php_group:php:7.1.5:*:*:*:*:*:*:*

External links

https: 
https://bugs.php.net/bug.php?id=74593

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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

2) Improper input validation

EUVDB-ID: #VU10335

Risk: Low

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2017-8923

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform denial of service (DoS) attack.

The vulnerability exists due to insufficient input validation in zend_string_extend() function in Zend/zend_string.h when leveraging a script's use of ".=" with a long. The application does not prevent changes to string objects that can result in a negative length. A remote attacker can pass an overly long string to script, which uses ".=" operand on the supplied data and trigger application crash.

Mitigation

Update to version 5.6.31, 7.0.20 or 7.1.6.

Vulnerable software versions

PHP: 5.5.0 - 7.1.5

CPE2.3

• cpe:2.3:a:php_group:php:5.5.38:*:*:*:*:*:*:*
• cpe:2.3:a:php_group:php:5.6.30:*:*:*:*:*:*:*
• cpe:2.3:a:php_group:php:7.0.19:*:*:*:*:*:*:*
• cpe:2.3:a:php_group:php:7.1.5:*:*:*:*:*:*:*

External links

https://bugs.php.net/bug.php?id=74577
https://bugs.php.net/bug.php?id=73122

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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