CVE-2019-25036

unbound: assertion failure and denial of service in synth_cname

Severity Score

7.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Unbound before 1.9.5 allows an assertion failure and denial of service in synth_cname. NOTE: The vendor disputes that this is a vulnerability. Although the code may be vulnerable, a running Unbound installation cannot be remotely or locally exploited

** EN DISPUTA ** Unbound versiones anteriores a 1.9.5, permite un error de aserción y denegación de servicio en la función synth_cname. NOTA: El proveedor niega que esto sea una vulnerabilidad. Aunque el código puede ser vulnerable, una instalación de Unbound en funcionamiento no puede ser explotada de forma remota o local

A flaw was found in unbound. A reachable assertion in the synth_cname function can be triggered by sending invalid packets to the server. If asserts are disabled during compilation, this issue might lead to an out-of-bounds write in dname_pkt_copy function. The highest threat from this vulnerability is to data confidentiality and integrity as well as service availability.

*Credits: N/A

CVSS Scores

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Network

Attack Complexity

Low

Authentication

None

Confidentiality

None

Integrity

None

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-04-27 CVE Reserved
2021-04-27 CVE Published
2024-05-14 EPSS Updated
2024-08-05 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-617: Reachable Assertion
CWE-787: Out-of-bounds Write

CAPEC

References (5)

URL	Tag	Source
https://lists.debian.org/debian-lts-announce/2021/05/msg00007.html	Mailing List
https://security.netapp.com/advisory/ntap-20210507-0007	Third Party Advisory

URL	Date	SRC

URL	Date	SRC
https://ostif.org/our-audit-of-unbound-dns-by-x41-d-sec-full-results	2024-05-17

URL	Date	SRC
https://access.redhat.com/security/cve/CVE-2019-25036	2022-02-22
https://bugzilla.redhat.com/show_bug.cgi?id=1954782	2022-02-22

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Nlnetlabs Search vendor "Nlnetlabs"		Unbound Search vendor "Nlnetlabs" for product "Unbound"				< 1.9.5 Search vendor "Nlnetlabs" for product "Unbound" and version " < 1.9.5"		-		Affected
Debian Search vendor "Debian"		Debian Linux Search vendor "Debian" for product "Debian Linux"				9.0 Search vendor "Debian" for product "Debian Linux" and version "9.0"		-		Affected