CVE-2019-13117 — In numbers

In numbers.c in libxslt 1.1.33, an xsl:number with certain format strings could lead to a uninitialized read in xsltNumberFormatInsertNumbers. This could allow an attacker to discern whether a byte on the stack contains the characters A, a, I, i, or 0, or any other character.

01What is this vulnerability?

In numbers.c in libxslt 1.1.33, an xsl:number with certain format strings could lead to a uninitialized read in xsltNumberFormatInsertNumbers. This could allow an attacker to discern whether a byte on the stack contains the characters A, a, I, i, or 0, or any other character.

02Affected products

No structured affected-product list available — see references below for vendor advisories.

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: 2019-07-01T02:15:09.737
• Last modified: 2026-05-28T19:16:29.543

09References

• lists.opensuse.org — http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00062.html
• www.openwall.com — http://www.openwall.com/lists/oss-security/2019/11/17/2
• bugs.chromium.org — https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=14471
• gitlab.gnome.org — https://gitlab.gnome.org/GNOME/libxslt/commit/c5eb6cf3aba0af048596106ed839b4ae17…
• lists.apache.org — https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e3…
• lists.apache.org — https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8…
• lists.debian.org — https://lists.debian.org/debian-lts-announce/2019/07/msg00020.html
• lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…
• oss-fuzz.com — https://oss-fuzz.com/testcase-detail/5631739747106816
• security.netapp.com — https://security.netapp.com/advisory/ntap-20190806-0004/