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NVD / CVE Program· CNA mitre

CVE-2018-1000001: In glibc 2.26 and earlier there is confusion in the usage of getcwd() by realpath() which can be used to write before the destination buffer

Noroxi assessment

Priority: Plan (action score 40/100)

  • A ready-made attack module is public (Metasploit); exploiting it takes no special expertise.
  • Because a ready-made attack tool exists, priority is at least “Plan”.
  • Probability of exploitation in the next 30 days: 13.3% (FIRST EPSS); higher than 96.3% of all records.
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: glibc (Debian:12) 2.26-4; glibc (openSUSE:Tumbleweed) 2.34-1.2; glibc (Red Hat:enterprise_linux:7::client) 0:2.17-222.el7.

Add it to your regular patch cycle. Upgrade to glibc (Debian:12) 2.26-4; glibc (openSUSE:Tumbleweed) 2.34-1.2; glibc (Red Hat:enterprise_linux:7::client) 0:2.17-222.el7 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In glibc 2.26 and earlier there is confusion in the usage of getcwd() by realpath() which can be used to write before the destination buffer leading to a buffer underflow and potential code execution.

HighCVSS 7.8 · v3.0—Weaponized Fix available
Published
Jan 31, 2018
Updated
Jun 16, 2026
EPSS
13.3% · 96th percentile

Report tools

JSON

Action score

40

Plan

Add it to your regular patch cycle.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
4 / 30 · 13.3%
Ready-made attack tool
5 / 40 · floor: at least 40

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Weaponized exploit exists
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
gnuglibc
canonicalubuntu linux
redhatvirtualization host
redhatenterprise linux desktop
redhatenterprise linux server
redhatenterprise linux server aus
redhatenterprise linux server eus
redhatenterprise linux server tus
redhatenterprise linux workstation

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • canonical ubuntu linux12.04
  • canonical ubuntu linux14.04
  • canonical ubuntu linux16.04
  • canonical ubuntu linux17.10
  • gnu glibcup to 2.26 inclusive
  • redhat enterprise linux desktop7.0
  • redhat enterprise linux server7.0
  • redhat enterprise linux server aus7.6
  • redhat enterprise linux server eus7.6
  • redhat enterprise linux server tus7.6
  • redhat enterprise linux workstation7.0
  • redhat virtualization host4.0

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12glibcbefore 2.26-42.26-4
openSUSE:Tumbleweedglibcbefore 2.34-1.22.34-1.2
Red Hat:enterprise_linux:7::clientglibcbefore 0:2.17-222.el70:2.17-222.el7
Red Hat:enterprise_linux:7::clientglibc-commonbefore 0:2.17-222.el70:2.17-222.el7
Red Hat:enterprise_linux:7::clientglibc-debuginfobefore 0:2.17-222.el70:2.17-222.el7
Red Hat:enterprise_linux:7::clientglibc-debuginfo-commonbefore 0:2.17-222.el70:2.17-222.el7
Red Hat:enterprise_linux:7::clientglibc-develbefore 0:2.17-222.el70:2.17-222.el7
Red Hat:enterprise_linux:7::clientglibc-headersbefore 0:2.17-222.el70:2.17-222.el7
Red Hat:enterprise_linux:7::clientglibc-staticbefore 0:2.17-222.el70:2.17-222.el7
Red Hat:enterprise_linux:7::clientglibc-utilsbefore 0:2.17-222.el70:2.17-222.el7
Red Hat:enterprise_linux:7::clientnscdbefore 0:2.17-222.el70:2.17-222.el7
SUSE:Linux Enterprise Desktop 12 SP2glibcbefore 2.22-62.6.22.22-62.6.2
SUSE:Linux Enterprise Desktop 12 SP2glibcbefore 2.22-62.3.42.22-62.3.4
SUSE:Linux Enterprise Server 12-LTSSglibcbefore 2.19-22.24.52.19-22.24.5
SUSE:Linux Enterprise Server 12-LTSSglibcbefore 2.19-22.27.9582.19-22.27.958
SUSE:Linux Enterprise Software Development Kit 11 SP4glibcbefore 2.11.3-17.110.6.22.11.3-17.110.6.2
SUSE:Linux Enterprise Software Development Kit 11 SP4glibcbefore 2.11.3-17.110.3.12.11.3-17.110.3.1
SUSE:OpenStack Cloud 6glibcbefore 2.19-40.9.52.19-40.9.5

Same product

gnu: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-4911Glibc: buffer overflow in ld.so leading to privilege escalationKEV
    80Now
  • CVE-2015-0235Heap-based buffer overflow in the __nss_hostname_digits_dots function in glibc 2.2, and other 2.x versions before 2.18, allows context-depen
    68This week
  • CVE-2015-7547Multiple stack-based buffer overflows in the (1) send_dg and (2) send_vc functions in the libresolv library in the GNU C Library (aka glibc
    59Plan

Published before and after this one in the same product

  • ← EarlierCVE-2017-17426Dec 5, 2017 · The malloc function in the GNU C Library (aka glibc or libc6) 2.26 could return a memory block that is too small if an attempt is made to al
    32Monitor
  • ← EarlierCVE-2017-16997Dec 17, 2017 · elf/dl-load.c in the GNU C Library (aka glibc or libc6) 2.19 through 2.26 mishandles RPATH and RUNPATH containing $ORIGIN for a privileged (
    32Monitor
  • Later →CVE-2017-1000408Feb 1, 2018 · A memory leak in glibc 2.1.1 (released on May 24, 1999) can be reached and amplified through the LD_HWCAP_MASK environment variable.
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:glibc2.26-4 · Debian:12Package registry (OSV)
opensuse:glibc2.34-1.2 · openSUSE:TumbleweedPackage registry (OSV)
red hat:glibc0:2.17-222.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:glibc-common0:2.17-222.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:glibc-debuginfo0:2.17-222.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:glibc-debuginfo-common0:2.17-222.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:glibc-devel0:2.17-222.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:glibc-headers0:2.17-222.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:glibc-static0:2.17-222.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:glibc-utils0:2.17-222.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:nscd0:2.17-222.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
suse:glibc2.19-40.9.5 · SUSE:OpenStack Cloud 6Package registry (OSV)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Metasploit module ×1
  • Exploit-DB entry ×3
  • Proof-of-concept repository on GitHub ×2

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Exploit-DB entrylocal2018-06-13
Exploit-DB entrylocal2018-06-13
Exploit-DB entrylocal2018-01-16
Metasploit moduleexploit/linux/local/glibc_realpath_priv_escglibc 'realpath()' Privilege Escalationexploit2018-01-16
Proof-of-concept repository on GitHubstars:312018-02-07
Proof-of-concept repository on GitHubstars:02022-03-01

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. First PoC-15 d
  2. Metasploit-15 d
  3. Published
  4. TodayOct 27, 2026+3191 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records