Multiple vulnerabilities in VirusTotal YARA

1) Uncontrolled Recursion

EUVDB-ID: #VU38920

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-9438

CWE-ID: CWE-674 - Uncontrolled Recursion

Exploit availability: No

Description

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

libyara/re.c in the regexp module in YARA 3.5.0 allows remote attackers to cause a denial of service (stack consumption) via a crafted rule (involving hex strings) that is mishandled in the _yr_re_emit function, a different vulnerability than CVE-2017-9304.

Mitigation

Install update from vendor's website.

Vulnerable software versions

YARA: 3.5.0

External links

http://github.com/VirusTotal/yara/commit/10e8bd3071677dd1fa76beeef4bc2fc427cea5e7
http://github.com/VirusTotal/yara/issues/674

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application 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) Uncontrolled Recursion

EUVDB-ID: #VU38930

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-9304

CWE-ID: CWE-674 - Uncontrolled Recursion

Exploit availability: No

Description

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

libyara/re.c in the regexp module in YARA 3.5.0 allows remote attackers to cause a denial of service (stack consumption) via a crafted rule that is mishandled in the _yr_re_emit function.

Mitigation

Install update from vendor's website.

Vulnerable software versions

YARA: 3.5.0

External links

http://github.com/VirusTotal/yara/commit/925bcf3c3b0a28b5b78e25d9efda5c0bf27ae699
http://github.com/VirusTotal/yara/issues/674

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application 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) Use-after-free

EUVDB-ID: #VU38995

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-8929

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error when processing a crafted rule. A remote attackers can cause a denial of service (use-after-free and application crash).

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Mitigation

Install update from vendor's website.

Vulnerable software versions

YARA: 3.5.0

External links

http://github.com/VirusTotal/yara/commit/053e67e3ec81cc9268ce30eaf0d6663d8639ed1e
http://github.com/VirusTotal/yara/issues/658

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application 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) Out-of-bounds read

EUVDB-ID: #VU39100

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-8294

CWE-ID: CWE-125 - Out-of-bounds read

Exploit availability: No

Description

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

The vulnerability exists due to a boundary condition within the the regex component function in YARA 3.5.0 allows remote attackers to cause a denial of service (out-of-bounds read and application crash) via a crafted rule that is mishandled file. A remote attacker can create a specially crafted file, trick the victim into opening it, trigger out-of-bounds read error and crash the affected application.

Mitigation

Install update from vendor's website.

Vulnerable software versions

YARA: 3.5.0

External links

http://www.securityfocus.com/bid/98072
http://github.com/VirusTotal/yara/commit/83d799804648c2a0895d40a19835d9b757c6fa4e
http://github.com/VirusTotal/yara/issues/646

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application 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) Out-of-bounds read

EUVDB-ID: #VU39292

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-5923

CWE-ID: CWE-125 - Out-of-bounds read

Exploit availability: No

Description

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

libyara/grammar.y in YARA 3.5.0 allows remote attackers to cause a denial of service (heap-based out-of-bounds read and application crash) via a crafted rule that is mishandled in the yara_yyparse function.

Mitigation

Install update from vendor's website.

Vulnerable software versions

YARA: 3.5.0

External links

http://www.securityfocus.com/bid/98080
http://github.com/VirusTotal/yara/commit/ab906da53ff2a68c6fd6d1fa73f2b7c7bf0bc636
http://github.com/VirusTotal/yara/issues/597

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application 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) Use-after-free

EUVDB-ID: #VU39293

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-5924

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error when processing a crafted rule that is mishandled in the yr_compiler_destroy function. A remote attackers can cause a denial of service (use-after-free and application crash).

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Mitigation

Install update from vendor's website.

Vulnerable software versions

YARA: 3.5.0

External links

http://www.securityfocus.com/bid/98075
http://github.com/VirusTotal/yara/commit/7f02eca670f29c00a1d2c305e96febae6ce5d37b
http://github.com/VirusTotal/yara/issues/593

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

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

Is there known malware, which exploits this vulnerability?

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

7) NULL pointer dereference

EUVDB-ID: #VU39299

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-10210

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

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

The vulnerability exists due to a NULL pointer dereference error. A remote attacker can trigger denial of service conditions via a crafted rule that is mishandled in the yy_get_next_buffer function.

Mitigation

Install update from vendor's website.

Vulnerable software versions

YARA: 3.5.0

External links

http://www.securityfocus.com/bid/98077
http://github.com/VirusTotal/yara/commit/3119b232c9c453c98d8fa8b6ae4e37ba18117cd4
http://github.com/VirusTotal/yara/issues/576

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

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

Is there known malware, which exploits this vulnerability?

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

8) Use-after-free

EUVDB-ID: #VU39300

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-10211

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error when processing a crafted rule that is mishandled in the yr_parser_lookup_loop_variable function. A remote attackers can cause a denial of service (use-after-free and application crash).

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

Mitigation

Install update from vendor's website.

Vulnerable software versions

YARA: 3.5.0

External links

http://www.securityfocus.com/bid/98078
http://github.com/VirusTotal/yara/commit/890c3f850293176c0e996a602ffa88b315f4e98f
http://github.com/VirusTotal/yara/issues/575

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

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

Is there known malware, which exploits this vulnerability?

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