# CVE-2018-1000001: Memory corruption in n/a

> A buffer underflow in glibc's realpath function allows attackers to execute arbitrary code via crafted inputs.

- **Severity:** High 7.8 (`CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 31 Jan 2018
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2018-1000001, GHSA-gxfx-pp2w-7f8c, SUSE-SU-2018:0071-1, SUSE-SU-2018:0075-1, UBUNTU-CVE-2018-1000001

## What is CVE-2018-1000001?

CVE-2018-1000001 is a high-severity memory corruption vulnerability in Canonical Ubuntu Linux, published on 31 Jan 2018. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2018-1000001?

It affects 9 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `glibc` | SUSE:Linux Enterprise Point of Sale 11 SP3 | All versions | 2.11.3-17.110.3.1 |
| `glibc` | SUSE:Linux Enterprise Server 11 SP3-LTSS | All versions | 2.11.3-17.110.3.1 |
| `glibc` | SUSE:Linux Enterprise Server 11 SP3-TERADATA | All versions | 2.11.3-17.110.3.1 |
| `glibc` | SUSE:Linux Enterprise Server 11 SP4 | All versions | 2.11.3-17.110.3.1 |
| `glibc` | SUSE:Linux Enterprise Server 12 SP1-LTSS | All versions | 2.19-40.9.5 |
| `glibc` | SUSE:Linux Enterprise Server for SAP Applications 11 SP4 | All versions | 2.11.3-17.110.3.1 |
| `glibc` | SUSE:Linux Enterprise Server for SAP Applications 12 SP1 | All versions | 2.19-40.9.5 |
| `glibc` | SUSE:Linux Enterprise Software Development Kit 11 SP4 | All versions | 2.11.3-17.110.3.1 |
| `glibc` | SUSE:OpenStack Cloud 6 | All versions | 2.19-40.9.5 |

Products: Canonical Ubuntu Linux, Gnu Glibc, Redhat Enterprise Linux Desktop, Redhat Enterprise Linux Server, Redhat Enterprise Linux Server Aus, Redhat Enterprise Linux Server Eus, Redhat Enterprise Linux Server Tus, Redhat Enterprise Linux Workstation, Redhat Virtualization Host.

## How do I fix CVE-2018-1000001?

Apply the vendor's patch.

## Is CVE-2018-1000001 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-1000001 exists.

Public exploit code:

- glibc getcwd() local privilege escalation compiled binaries (github_poc): https://github.com/0x00-0x00/CVE-2018-1000001
- glibc < 2.26 - 'getcwd()' Local Privilege Escalation (exploitdb)
- glibc 'realpath()' Privilege Escalation (metasploit)
- glibc - 'realpath()' Privilege Escalation (Metasploit) (exploitdb)
- glibc - 'realpath()' Privilege Escalation (Metasploit) (exploitdb)
- Tools for get offsets and adding patch for support i386 (github_poc): https://github.com/usernameid0/tools-for-CVE-2018-1000001

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-1000001 and fix it if it is affected.

What it is: CVE-2018-1000001 is a high-severity memory corruption vulnerability in Canonical Ubuntu Linux, published on 31 Jan 2018. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-1000001 exists.

Affected product: Canonical Ubuntu Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2018-1000001/ (Markdown: https://insights.sbomify.com/CVE-2018-1000001/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-1000001
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-1000001
- OSV: https://osv.dev/vulnerability/CVE-2018-1000001

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-1000001/
Summaries are generated and may contain mistakes; the official description above is the record.