CVE-2018-17942 — The convert_to_decimal function in vasnprintf

The convert_to_decimal function in vasnprintf.c in Gnulib before 2018-09-23 has a heap-based buffer overflow because memory is not allocated for a trailing '\0' character during %f processing.

01What is this vulnerability?

The convert_to_decimal function in vasnprintf.c in Gnulib before 2018-09-23 has a heap-based buffer overflow because memory is not allocated for a trailing '\0' character during %f processing.

02Affected products

Vendor	Product	Versions
n	a / n/a	n/a

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2018-10-03T08:00:00.000Z
• Last modified: 2024-08-05T11:01:14.605Z

09References

• github.com — https://github.com/coreutils/gnulib/commit/278b4175c9d7dd47c1a3071554aac02add3b3…
• savannah.gnu.org — https://savannah.gnu.org/bugs/?func=detailitem&item_id=54686
• lists.gnu.org — https://lists.gnu.org/archive/html/bug-gnulib/2018-09/msg00107.html
• lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…
• lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…