Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
None
Attack Vector
Network
0

CVE-2023-31137

Disclosure Date: May 09, 2023 •
CVE-2023-31137 CVSS v3 Base Score: 7.5
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

MaraDNS is open-source software that implements the Domain Name System (DNS). In version 3.5.0024 and prior, a remotely exploitable integer underflow vulnerability in the DNS packet decompression function allows an attacker to cause a Denial of Service by triggering an abnormal program termination.

The vulnerability exists in the decomp_get_rddata function within the Decompress.c file. When handling a DNS packet with an Answer RR of qtype 16 (TXT record) and any qclass, if the rdlength is smaller than rdata, the result of the line Decompress.c:886 is a negative number len = rdlength - total;. This value is then passed to the decomp_append_bytes function without proper validation, causing the program to attempt to allocate a massive chunk of memory that is impossible to allocate. Consequently, the program exits with an error code of 64, causing a Denial of Service.

One proposed fix for this vulnerability is to patch Decompress.c:887 by breaking if(len <= 0), which has been incorporated in version 3.5.0036 via commit bab062bde40b2ae8a91eecd522e84d8b993bab58.

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CVSS V3 Severity and Metrics
Base Score:
7.5 High
Impact Score:
3.6
Exploitability Score:
3.9
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector (AV):
Network
Attack Complexity (AC):
Low
Privileges Required (PR):
None
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
None
Integrity (I):
None
Availability (A):
High

General Information

Offensive Application
Unknown
Utility Class
Unknown
Ports
Unknown
OS
Unknown
Vulnerable Versions
MaraDNS <= 3.5.0024
Prerequisites
Unknown
Discovered By
Unknown
PoC Author
Unknown
Metasploit Module
Unknown
Reporter
Unknown

Vendors

  • debian,
  • fedoraproject,
  • maradns

Products

  • debian linux 10.0,
  • debian linux 11.0,
  • fedora 37,
  • fedora 38,
  • maradns
Technical Analysis