Buffer overflow in Haxx Libcurl

CVE-2018-14618

curl before version 7.61.1 is vulnerable to a buffer overrun in the NTLM authentication code. The internal function Curl_ntlm_core_mk_nt_hash multiplies the length of the password by two (SUM) to figure out how large temporary storage area to allocate from the heap. The length value is then subsequently used to iterate over the password and generate output into the allocated storage buffer. On systems with a 32 bit size_t, the math to calculate SUM triggers an integer overflow when the password length exceeds 2GB (2^31 bytes). This integer overflow usually causes a very small buffer to actually get allocated instead of the intended very huge one, making the use of that buffer end up in a heap buffer overflow. (This bug is almost identical to CVE-2017-8816.)

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.111 (95.9th percentile), scored .

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 96th percentile — 95.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2018-14618: held from 0.111 to 0.111.

EPSS over last 30 days · oldest: 0.111 · newest: 0.111 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2018-14618?
CVE-2018-14618 is a high-severity vulnerability in Haxx Libcurl, classified under Heap-based Buffer Overflow. CVSS score: 7.5/10. Published 2018-09-05.
How severe is CVE-2018-14618?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2018-14618 known to be exploited?
9 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.