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Fencer Vulns
medium 4.3

CVE-2018-16839 json

Curl versions 7.33.0 through 7.61.1 are vulnerable to a buffer overrun in the SASL authentication code that may lead to denial of service.

published 2018-10-31 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-8635

cvss
4.3
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
5.8%
EPSS 5.8% chance of exploitation in 30 days, percentile 93%
public exploits
0
none known

Summary

Curl versions 7.33.0 through 7.61.1 are vulnerable to a buffer overrun in the SASL authentication code that may lead to denial of service.

Patch / fix

  • curl Debian 14, Debian 13, Debian 12 7.62.0-1

debian advisories DEBIAN-CVE-2018-16839

  • curl Ubuntu 14.04 LTS 7.35.0-1ubuntu2.19
  • curl Ubuntu 16.04 LTS 7.47.0-1ubuntu2.11
  • curl Ubuntu 18.04 LTS 7.58.0-2ubuntu3.5

ubuntu advisories UBUNTU-CVE-2018-16839

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • curl SLES for SAP 12 SP3, SLES for SAP 12 SP2, SLES for SAP 12 SP1 +9 more 7.37.0-37.37.1
  • curl SLES for SAP 12 SP4, SLES 12 SP4, SLED 12 SP4 +1 more 7.60.0-4.3.1
  • curl SLE Module for Basesystem 15 7.60.0-3.14.3

suse advisories SUSE-SU-2019:0996-1SUSE-SU-2019:0339-1SUSE-SU-2018:3624-1

  • curl openSUSE Tumbleweed 7.79.1-1.1

opensuse advisories openSUSE-SU-2024:10582-1

  • curl Alpine 3.24, Alpine 3.23, Alpine 3.22 +13 more 7.62.0-r0
  • curl Alpine 3.8, Alpine 3.7, Alpine 3.6 +1 more 7.61.1-r1

alpine advisories ALPINE-CVE-2018-16839

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • lib32-curl Arch Linux 7.62.0-1
  • lib32-libcurl-compat Arch Linux 7.62.0-1
  • lib32-libcurl-gnutls Arch Linux 7.62.0-1

arch linux advisories AVG-796AVG-797AVG-798

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2018-16839 updated cvss 5.0

curl: Integer overflow leading to heap-based buffer overflow in Curl_sasl_create_plain_message()

  • Red Hat .NET Core 1.0 on Red Hat Enterprise Linux rh-dotnetcore10-curl Red Hat .NET Core 1.1 on Red Hat Enterprise Linux rh-dotnetcore11-curl Red Hat .NET Core 2.1 on Red Hat Enterprise Linux rh-dotnet21-curl, rh-dotnet21-libcurl
    affected: no fix planned “Out of support scope”
  • Red Hat JBoss Core Services jbcs-httpd24-curl jbcs-httpd24-curl
    affected: no fix available
  • Red Hat Software Collections httpd24-curl, httpd24-libcurl
    affected: no fix available “Fix deferred”
  • Red Hat JBoss Core Services Apache HTTP Server 2.4.29 SP2
    fixed: vendor fix RHSA-2019:1543
  • Red Hat Enterprise Linux 5 curl Red Hat Enterprise Linux 6 curl, libcurl Red Hat Enterprise Linux 7 curl, libcurl Red Hat Enterprise Linux 8 curl, libcurl, libcurl-minimal Red Hat JBoss Web Server 5 curl
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
6 mo ago

Exploit prediction

5.78% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.0 4.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
NVD 3.0 9.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • The Curl Project curl:

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound
  • CWE-122 Heap-based Buffer Overflow
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.