# CVE-2015-3636: Use after free in n/a

> Local attackers can exploit a use-after-free in the Linux kernel ping implementation to escalate privileges or crash the system.

- **Severity:** Medium 4.9 (`AV:L/AC:L/Au:N/C:N/I:N/A:C`)
- **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:** 6 Aug 2015
- **Updated:** 6 Aug 2024
- **Also known as:** DEBIAN-CVE-2015-3636, GHSA-67pv-68g5-4j93, RHSA-2015:1583, RHSA-2015:1643, UBUNTU-CVE-2015-3636

## What is CVE-2015-3636?

CVE-2015-3636 is a medium-severity use after free vulnerability in Canonical Ubuntu Linux, published on 6 Aug 2015. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The ping_unhash function in net/ipv4/ping.c in the Linux kernel before 4.0.3 does not initialize a certain list data structure during an unhash operation, which allows local users to gain privileges or cause a denial of service (use-after-free and system crash) by leveraging the ability to make a SOCK_DGRAM socket system call for the IPPROTO_ICMP or IPPROTO_ICMPV6 protocol, and then making a connect system call after a disconnect.

## Which versions are affected by CVE-2015-3636?

It affects 4 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `kernel` | Red Hat:rhel_aus:6.4::server | All versions | 0:2.6.32-358.65.1.el6 |
| `kernel-debug` | Red Hat:rhel_aus:6.4::server | All versions | 0:2.6.32-358.65.1.el6 |
| `kernel-debug-debuginfo` | Red Hat:rhel_aus:6.4::server | All versions | 0:2.6.32-358.65.1.el6 |
| `kernel-debug-devel` | Red Hat:rhel_aus:6.4::server | All versions | 0:2.6.32-358.65.1.el6 |
| `kernel-debuginfo` | Red Hat:rhel_aus:6.4::server | All versions | 0:2.6.32-358.65.1.el6 |
| `kernel-debuginfo-common-x86_64` | Red Hat:rhel_aus:6.4::server | All versions | 0:2.6.32-358.65.1.el6 |
| `kernel-devel` | Red Hat:rhel_aus:6.4::server | All versions | 0:2.6.32-358.65.1.el6 |
| `kernel-doc` | Red Hat:rhel_aus:6.4::server | All versions | 0:2.6.32-358.65.1.el6 |
| `kernel-firmware` | Red Hat:rhel_aus:6.4::server | All versions | 0:2.6.32-358.65.1.el6 |
| `kernel-headers` | Red Hat:rhel_aus:6.4::server | All versions | 0:2.6.32-358.65.1.el6 |
| `perf` | Red Hat:rhel_aus:6.4::server | All versions | 0:2.6.32-358.65.1.el6 |
| `perf-debuginfo` | Red Hat:rhel_aus:6.4::server | All versions | 0:2.6.32-358.65.1.el6 |
| `python-perf` | Red Hat:rhel_aus:6.4::server | All versions | 0:2.6.32-358.65.1.el6 |
| `python-perf-debuginfo` | Red Hat:rhel_aus:6.4::server | All versions | 0:2.6.32-358.65.1.el6 |
| `kernel` | Red Hat:rhel_eus:6.5::computenode | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-abi-whitelists` | Red Hat:rhel_eus:6.5::computenode | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-debug` | Red Hat:rhel_eus:6.5::computenode | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-debug-debuginfo` | Red Hat:rhel_eus:6.5::computenode | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-debug-devel` | Red Hat:rhel_eus:6.5::computenode | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-debuginfo` | Red Hat:rhel_eus:6.5::computenode | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-debuginfo-common-x86_64` | Red Hat:rhel_eus:6.5::computenode | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-devel` | Red Hat:rhel_eus:6.5::computenode | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-doc` | Red Hat:rhel_eus:6.5::computenode | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-firmware` | Red Hat:rhel_eus:6.5::computenode | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-headers` | Red Hat:rhel_eus:6.5::computenode | All versions | 0:2.6.32-431.61.2.el6 |
| `perf` | Red Hat:rhel_eus:6.5::computenode | All versions | 0:2.6.32-431.61.2.el6 |
| `perf-debuginfo` | Red Hat:rhel_eus:6.5::computenode | All versions | 0:2.6.32-431.61.2.el6 |
| `python-perf` | Red Hat:rhel_eus:6.5::computenode | All versions | 0:2.6.32-431.61.2.el6 |
| `python-perf-debuginfo` | Red Hat:rhel_eus:6.5::computenode | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel` | Red Hat:rhel_eus:6.5::server | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-abi-whitelists` | Red Hat:rhel_eus:6.5::server | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-bootwrapper` | Red Hat:rhel_eus:6.5::server | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-debug` | Red Hat:rhel_eus:6.5::server | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-debug-debuginfo` | Red Hat:rhel_eus:6.5::server | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-debug-devel` | Red Hat:rhel_eus:6.5::server | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-debuginfo` | Red Hat:rhel_eus:6.5::server | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-debuginfo-common-i686` | Red Hat:rhel_eus:6.5::server | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-debuginfo-common-ppc64` | Red Hat:rhel_eus:6.5::server | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-debuginfo-common-s390x` | Red Hat:rhel_eus:6.5::server | All versions | 0:2.6.32-431.61.2.el6 |
| `kernel-debuginfo-common-x86_64` | Red Hat:rhel_eus:6.5::server | All versions | 0:2.6.32-431.61.2.el6 |

Products: Canonical Ubuntu Linux, Debian Debian Linux, Linux kernel, Redhat Enterprise Linux.

## How do I fix CVE-2015-3636?

Apply the vendor's patch.

## Is CVE-2015-3636 being exploited?

There is no known exploitation of CVE-2015-3636 in the wild and no public exploit code.

Public exploit code:

- PoC code for 32 bit Android OS (github_poc): https://github.com/fi01/CVE-2015-3636
- CVE-2015-3636 exploit  (github_poc): https://github.com/android-rooting-tools/libpingpong_exploit
- Expolit for android (goldfish kernel v3.10.0+) on arm64 with PXN&SELinux Bypassed. Based on fi01's code. (github_poc): https://github.com/a7vinx/CVE-2015-3636
- https://github.com/betalphafai/cve-2015-3636_crash (github_poc): https://github.com/betalphafai/cve-2015-3636_crash
- CVE-2015-3636 exploit (github_poc): https://github.com/askk/libping_unhash_exploit_POC
- root with CVE-2015-3636 (github_poc): https://github.com/debugfan/rattle_root

## 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-2015-3636 and fix it if it is affected.

What it is: CVE-2015-3636 is a medium-severity use after free vulnerability in Canonical Ubuntu Linux, published on 6 Aug 2015. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2015-3636 in the wild and no public exploit code.

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-2015-3636/ (Markdown: https://insights.sbomify.com/CVE-2015-3636/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2015-3636
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2015-3636
- OSV: https://osv.dev/vulnerability/CVE-2015-3636

---
From sbomify Insights: https://insights.sbomify.com/CVE-2015-3636/
Summaries are generated and may contain mistakes; the official description above is the record.