c-ares is an asynchronous resolver library. Prior to 1.34.7, ares_dns_name_parse() enforces backward DNS compression pointers but does not bound the total pointer hops or assembled name length. A malicious DNS server can send a response containing a long descending pointer chain...
Vendor
c-ares vulnerabilities
14 published CVES affecting c-ares, from public sources (CVE.org, NVD, CISA KEV, FIRST EPSS, OSV).
- Total
- 14
- Critical
- 1
- High
- 5
- Medium
- 6
- Low
- 2
- Unscored
- 0
- CISA KEV
- 0
Products
Latest c-ares CVEs
Newest publication first
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HighCVSS 7.5 EPSS 0.48%
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MediumCVSS 5.3 EPSS 0.38%
c-ares is an asynchronous resolver library. Prior to 1.34.7, ares_dns_parse() trusts the attacker-controlled ANCOUNT, NSCOUNT, and ARCOUNT fields before confirming that the DNS response contains enough bytes for the claimed records. Because process_answer() invokes parsing before...
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HighCVSS 7.5 EPSS 0.85%
c-ares is an asynchronous resolver library. From ver 1.32.3 until 1.34.7, a use-after-free / double-free in c-ares' query-completion handling. The same flaw — a query's callback being invoked while the query is still linked in the channel's internal lookup structures — is present...
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CVE-2025-62408 c-ares has a Use After Free vulnerability when connection is cleaned up after error
PublishedMediumCVSS 5.9 EPSS 0.46%c-ares is an asynchronous resolver library. Versions 1.32.3 through 1.34.5 terminate a query after maximum attempts when using read_answer() and process_answer(), which can cause a Denial of Service. This issue is fixed in version 1.34.6.
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HighCVSS 8.3 EPSS 0.60%
c-ares is an asynchronous resolver library. From 1.32.3 through 1.34.4, there is a use-after-free in read_answers() when process_answer() may re-enqueue a query either due to a DNS Cookie Failure or when the upstream server does not properly support EDNS, or possibly on TCP queri...
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MediumCVSS 5.5 EPSS 0.35%
c-ares is a C library for asynchronous DNS requests. ares__read_line() is used to parse local configuration files such as /etc/resolv.conf, /etc/nsswitch.conf, the HOSTALIASES file, and if using a c-ares version prior to 1.27.0, the /etc/hosts file. If any of these configuration...
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MediumCVSS 5.9 EPSS 0.98%
Buffer overflow vulnerability in c-ares before 1_16_1 thru 1_17_0 via function ares_parse_soa_reply in ares_parse_soa_reply.c.
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HighCVSS 7.5 EPSS 1.6%
c-ares is an asynchronous resolver library. c-ares is vulnerable to denial of service. If a target resolver sends a query, the attacker forges a malformed UDP packet with a length of 0 and returns them to the target resolver. The target resolver erroneously interprets the 0 lengt...
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MediumCVSS 6.5 EPSS 0.91%
c-ares is an asynchronous resolver library. When /dev/urandom or RtlGenRandom() are unavailable, c-ares uses rand() to generate random numbers used for DNS query ids. This is not a CSPRNG, and it is also not seeded by srand() so will generate predictable output. Input from the ra...
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MediumCVSS 6.4 EPSS 0.39%
c-ares is an asynchronous resolver library. ares_inet_net_pton() is vulnerable to a buffer underflow for certain ipv6 addresses, in particular "0::00:00:00/2" was found to cause an issue. C-ares only uses this function internally for configuration purposes which would require an...
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LowCVSS 3.7 EPSS 0.94%
c-ares is an asynchronous resolver library. When cross-compiling c-ares and using the autotools build system, CARES_RANDOM_FILE will not be set, as seen when cross compiling aarch64 android. This will downgrade to using rand() as a fallback which could allow an attacker to take a...
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LowCVSS 3.3 EPSS 0.53%
A possible use-after-free and double-free in c-ares lib version 1.16.0 if ares_destroy() is called prior to ares_getaddrinfo() completing. This flaw possibly allows an attacker to crash the service that uses c-ares lib. The highest threat from this vulnerability is to this servic...
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HighCVSS 7.5 EPSS 3.3%
The c-ares function ares_parse_naptr_reply(), which is used for parsing NAPTR responses, could be triggered to read memory outside of the given input buffer if the passed in DNS response packet was crafted in a particular way.
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CriticalCVSS 9.8 EPSS 8.7%
Heap-based buffer overflow in the ares_create_query function in c-ares 1.x before 1.12.0 allows remote attackers to cause a denial of service (out-of-bounds write) or possibly execute arbitrary code via a hostname with an escaped trailing dot.
Sources: CVE.org, NVD, CISA KEV, FIRST EPSS, OSV and public exploit-reference metadata. Product matching comes from the published CVE records. A proof-of-concept means public code exists; it is not evidence of exploitation.