Denial of service in Zlib

Published: 2017-05-23 | Updated: 2025-02-27

Risk	Low
Patch available	YES
Number of vulnerabilities	4
CVE-ID	CVE-2016-9841 CVE-2016-9840 CVE-2016-9842 CVE-2016-9843
CWE-ID	CWE-125 CWE-20
Exploitation vector	Network
Public exploit	N/A
Vulnerable software	Zlib Universal components / Libraries / Libraries used by multiple products
Vendor	GNU

Security Bulletin

This security bulletin contains information about 4 vulnerabilities.

1) Denial of service

EUVDB-ID: #VU6664

Risk: Low

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

CVE-ID: CVE-2016-9841

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

Exploit availability: No

Description

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The weakness exists in zlib due to out-of-bounds pointer arithmetic in inftrees.c. A remote attacker can cause the application to crash.

Successful exploitation of the vulnerability results in denial of service.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Zlib: 1.2.0 - 1.2.8

CPE2.3

External links

https://github.com/madler/zlib/commit/9aaec95e82117c1cb0f9624264c3618fc380cecb
https://bugzilla.redhat.com/show_bug.cgi?id=1402346

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) Denial of service

EUVDB-ID: #VU6663

Risk: Low

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

CVE-ID: CVE-2016-9840

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

Exploit availability: No

Description

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The weakness exists in zlib due to out-of-bounds pointer arithmetic in inftrees.c. A remote attacker can send a specially crafted document, trick the victim into opening it, and cause the application to crash.

Successful exploitation of the vulnerability results in denial of service.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Zlib: 1.2.0 - 1.2.8

CPE2.3

External links

https://github.com/madler/zlib/commit/6a043145ca6e9c55184013841a67b2fef87e44c0
https://bugzilla.redhat.com/show_bug.cgi?id=1402345

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.

3) Denial of service

EUVDB-ID: #VU6665

Risk: Low

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

CVE-ID: CVE-2016-9842

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The weakness exists in zlib due to an undefined left shift of negative number. A remote attacker can send a specially crafted document, trick the victim into opening it, and cause the application to crash.

Successful exploitation of the vulnerability results in denial of service.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Zlib: 1.2.0 - 1.2.8

CPE2.3

External links

https://github.com/madler/zlib/commit/e54e1299404101a5a9d0cf5e45512b543967f958
https://bugzilla.redhat.com/show_bug.cgi?id=1402348

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.

4) Denial of service

EUVDB-ID: #VU6666

Risk: Low

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

CVE-ID: CVE-2016-9843

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

Exploit availability: No

Description

The vulnerability allows a remote attacker to cause DoS condition on the target system.

The weakness exists in zlib due to big-endian out-of-bounds pointer. A remote attacker can send a specially crafted document, trick the victim into opening it, and cause the application to crash.

Successful exploitation of the vulnerability results in denial of service.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Zlib: 1.2.0 - 1.2.8

CPE2.3

External links

https://aix.software.ibm.com/aix/efixes/security/java_apr2017_advisory.asc

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.