Out-of-bounds Read in Nongnu Libntlm
CVE-2019-17455
Libntlm through 1.5 relies on a fixed buffer size for tSmbNtlmAuthRequest, tSmbNtlmAuthChallenge, and tSmbNtlmAuthResponse read and write operations, as demonstrated by a stack-based buffer over-read in buildSmbNtlmAuthRequest in smbutil.c for a crafted NTLM request.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.031 (87.8th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 88th percentile — 87.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.031 · newest: 0.031 · change: 0.000
Affected products
- Nongnu Libntlm
- Canonical Ubuntu Linux — versions 14.04, 16.04, 18.04
- Debian Linux — versions 8.0, 9.0
- Fedoraproject Fedora — versions 32, 33
- openSUSE Backports Sle — versions 15.0
- openSUSE Leap — versions 15.1
Weakness classification (CWE)
Public proof-of-concept exploits
References
- gitlab.com/jas/libntlm/issues/2 (Exploit, Third Party Advisory)
- people.canonical.com/~ubuntu-security/cve/2019/CVE-2019-17455.html (Third Party Advisory)
- security-tracker.debian.org/tracker/CVE-2019-17455 (Third Party Advisory)
- bugs.debian.org/cgi-bin/bugreport.cgi (Exploit, Mailing List, Third Party Advisory, Issue Tracking)
- lists.debian.org/debian-lts-announce/2020/05/msg00010.html (mailing-list, Mailing List, Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2020-06/msg00029.html (vendor-advisory, Mailing List, Third Party Advisory)
- lists.opensuse.org/opensuse-security-announce/2020-06/msg00032.html (vendor-advisory, Mailing List, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.debian.org/debian-lts-announce/2021/11/msg00026.html (mailing-list, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2019-17455?
- CVE-2019-17455 is a critical-severity vulnerability in Nongnu Libntlm, classified under Out-of-bounds Read. CVSS score: 9.8/10. Published 2019-10-10.
- How severe is CVE-2019-17455?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2019-17455 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.