MaraDNS Integer Underflow Vulnerability in DNS Packet Decompression
Summary
MaraDNS Integer Underflow Vulnerability in DNS Packet Decompression
Original description
The description as published by the source.
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.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2023-31137 maradns Fixed in: 2.0.13-1.4+deb11u1
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- advisory debian.org
- patch github.com
- web github.com
- web lists.debian.org
- web lists.fedoraproject.org
- web lists.fedoraproject.org