CVE-2017-9107: An issue was discovered in adns before 1.5.2. It overruns reading a buffer if a domain ends with backslash. If the query domain ended with \, and adns...

Description

An issue was discovered in adns before 1.5.2. It overruns reading a buffer if a domain ends with backslash. If the query domain ended with \, and adns_qf_quoteok_query was specified, qdparselabel would read additional bytes from the buffer and try to treat them as the escape sequence. It would depart the input buffer and start processing many bytes of arbitrary heap data as if it were the query domain. Eventually it would run out of input or find some other kind of error, and declare the query domain invalid. But before then it might outrun available memory and crash. In principle this could be a denial of service attack.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

1.85%

76.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-119

Affected Software

Vendor	Product	Versions
Gnu	Adns	< 1.5.2
Fedoraproject	Fedora	31
Fedoraproject	Fedora	32

References

Timeline

Published: Jun 18, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2017-9107?

An issue was discovered in adns before 1.5.2. It overruns reading a buffer if a domain ends with backslash. If the query domain ended with \, and adns_qf_quoteok_query was specified, qdparselabel would read additional bytes from the buffer and try to treat them as the escape sequence. It would depart the input buffer and start processing many bytes of arbitrary heap data as if it were the query domain. Eventually it would run out of input or find some other kind of error, and declare the query domain invalid. But before then it might outrun available memory and crash. In principle this could be a denial of service attack.

How severe is CVE-2017-9107?

CVE-2017-9107 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.85% probability of exploitation in the next 30 days.

How do I fix CVE-2017-9107?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.