CVE-2018-16839: canonical ubuntu_linux Heap-based Buffer Overflow
Vulnerability summary
CVE-2018-16839 is a critical (CVSS 9.8) Heap-based Buffer Overflow vulnerability in canonical ubuntu_linux. EPSS estimates a 5.78% chance of exploitation in the next 30 days, higher than 93.1% of scored vulnerabilities.
Not severe (CVSS 4.3, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 6 · Related 4Timeline
- 31-10-2018PublishedVulnerability first disclosed.
- 15-04-2026Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
6 scores · 5 sources · 2 versions- CVE.orgCNA4.3MediumCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:LDiffers
- OSV · AlpineEcosystem advisory · calculated9.8CriticalCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated4.3MediumCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:LDiffers
- OSV · DebianEcosystem advisory · calculated9.8CriticalCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
5.78%
Chance of exploitation in the next 30 days
Percentile
93%
Versus all other CVEs
30-day change
No change 0.00 pp
From 5.78% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-122Heap-based Buffer OverflowThe product writes past the end of a buffer that was allocated on the heap.
- CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
- CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferThe product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.
Affected systems
Known conditions: network-reachable, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.
Suse12 products
- curl&distro=SUSE Enterprise Storage 4< 7.37.0-37.37.1
- curl&distro=SUSE Linux Enterprise Desktop 12 SP3< 7.37.0-37.37.1
- curl&distro=SUSE Linux Enterprise Server 12 SP1-LTSS< 7.37.0-37.37.1
- curl&distro=SUSE Linux Enterprise Server 12 SP2-BCL< 7.37.0-37.37.1
- curl&distro=SUSE Linux Enterprise Server 12 SP2-LTSS< 7.37.0-37.37.1
Debian2 products
- curl< 7.62.0-1
- debian_linuxEOL8.0 | 9.0
Alpine1 product
- curl≥ 7.33.0, < 7.62.0-r0 | ≥ 7.33.0, < 7.61.1-r1
Canonical1 product
- ubuntu_linuxEOL14.04 | 16.04 | 18.04 | 18.10
Haxx1 product
- curl≥ 7.33.0, ≤ 7.61.1
The curl project1 product
- curl:from 7.33.0 to 7.61.1
Ubuntu1 product
- curl< 7.35.0-1ubuntu2.19 | < 7.47.0-1ubuntu2.11 | < 7.58.0-2ubuntu3.5
7 vendors · 19 products
References
18 links
- lists.debian.org/debian-lts-announce/2018/11/msg00005.htmlMailing ListX Refsource MLISTThird Party Advisory
- github.com/curl/curl/commit/f3a24d7916b9173c69a3e0ee790102993833d6c5X Refsource CONFIRMPatchThird Party Advisory
- bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16839X Refsource CONFIRMIssue TrackingThird Party Advisory