CVE-2020-25683
dnsmasq: heap-based buffer overflow with large memcpy in get_rdata() when DNSSEC is enabled
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before it validates the received DNS entries. A remote attacker, who can create valid DNS replies, could use this flaw to cause an overflow in a heap-allocated memory. This flaw is caused by the lack of length checks in rfc1035.c:extract_name(), which could be abused to make the code execute memcpy() with a negative size in get_rdata() and cause a crash in dnsmasq, resulting in a denial of service. The highest threat from this vulnerability is to system availability.
Se encontró un fallo en dnsmasq versiones anteriores a 2.83. Se detectó un desbordamiento del búfer en la región heap de la memoria en dnsmasq cuando DNSSEC está habilitado y antes de comprobar las entradas DNS recibidas. Un atacante remoto, que puede crear respuestas DNS válidas, podría usar este fallo para causar un desbordamiento en una memoria asignada de la pila. Este fallo es causado por una falta de comprobación de longitud en rfc1035.c:extract_name(), que podría ser abusado para causar que el código ejecute memcpy() con un tamaño negativo en get_rdata() y causar un bloqueo en dnsmasq, lo que resultaría en una denegación de servicio. La mayor amenaza de esta vulnerabilidad es la disponibilidad del sistema
A flaw was found in dnsmasq. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before it validates the received DNS entries. A remote attacker, who can create valid DNS replies, could use this flaw to cause an overflow in a heap-allocated memory. This flaw is caused by the lack of length checks in rfc1035.c:extract_name(), which could be abused to make the code execute memcpy() with a negative size in get_rdata() and cause a crash in dnsmasq, resulting in a denial of service. The highest threat from this vulnerability is to system availability.
CVSS Scores
SSVC
- Decision:-
Timeline
- 2020-09-16 CVE Reserved
- 2021-01-19 CVE Published
- 2024-08-04 CVE Updated
- 2024-11-09 EPSS Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
- CWE-122: Heap-based Buffer Overflow
CAPEC
References (9)
URL | Tag | Source |
---|---|---|
https://lists.debian.org/debian-lts-announce/2021/03/msg00027.html | Mailing List | |
https://www.jsof-tech.com/disclosures/dnspooq | Third Party Advisory |
URL | Date | SRC |
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URL | Date | SRC |
---|---|---|
https://bugzilla.redhat.com/show_bug.cgi?id=1882018 | 2021-01-19 |
Affected Vendors, Products, and Versions
Vendor | Product | Version | Other | Status | ||||||
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Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
Thekelleys Search vendor "Thekelleys" | Dnsmasq Search vendor "Thekelleys" for product "Dnsmasq" | < 2.83 Search vendor "Thekelleys" for product "Dnsmasq" and version " < 2.83" | - |
Affected
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Fedoraproject Search vendor "Fedoraproject" | Fedora Search vendor "Fedoraproject" for product "Fedora" | 32 Search vendor "Fedoraproject" for product "Fedora" and version "32" | - |
Affected
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Fedoraproject Search vendor "Fedoraproject" | Fedora Search vendor "Fedoraproject" for product "Fedora" | 33 Search vendor "Fedoraproject" for product "Fedora" and version "33" | - |
Affected
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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
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Debian Search vendor "Debian" | Debian Linux Search vendor "Debian" for product "Debian Linux" | 10.0 Search vendor "Debian" for product "Debian Linux" and version "10.0" | - |
Affected
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