# CVE-2017-7805: Use after free in Firefox > A use-after-free flaw in Firefox TLS handshake processing allows attackers to cause a crash or potentially execute arbitrary code. - **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 11 Jun 2018 - **Updated:** 5 Aug 2024 - **Also known as:** DEBIAN-CVE-2017-7805, DLA-1138-1, DSA-3998-1, GHSA-595h-pjc7-9xf6, RHSA-2017:2832, UBUNTU-CVE-2017-7805, USN-3431-1 ## What is CVE-2017-7805? CVE-2017-7805 is a high-severity use after free vulnerability in Debian Debian Linux, published on 11 Jun 2018. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description During TLS 1.2 exchanges, handshake hashes are generated which point to a message buffer. This saved data is used for later messages but in some cases, the handshake transcript can exceed the space available in the current buffer, causing the allocation of a new buffer. This leaves a pointer pointing to the old, freed buffer, resulting in a use-after-free when handshake hashes are then calculated afterwards. This can result in a potentially exploitable crash. This vulnerability affects Firefox < 56, Firefox ESR < 52.4, and Thunderbird < 52.4. Weakness: CWE-416 (Use After Free) ## Which versions are affected by CVE-2017-7805? It affects 3 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `nss` | Red Hat:enterprise_linux:6::client | All versions | 0:3.28.4-4.el6_9 | | `nss-debuginfo` | Red Hat:enterprise_linux:6::client | All versions | 0:3.28.4-4.el6_9 | | `nss-devel` | Red Hat:enterprise_linux:6::client | All versions | 0:3.28.4-4.el6_9 | | `nss-pkcs11-devel` | Red Hat:enterprise_linux:6::client | All versions | 0:3.28.4-4.el6_9 | | `nss-sysinit` | Red Hat:enterprise_linux:6::client | All versions | 0:3.28.4-4.el6_9 | | `nss-tools` | Red Hat:enterprise_linux:6::client | All versions | 0:3.28.4-4.el6_9 | | `nss` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.28.4-4.el6_9 | | `nss-debuginfo` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.28.4-4.el6_9 | | `nss-devel` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.28.4-4.el6_9 | | `nss-pkcs11-devel` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.28.4-4.el6_9 | | `nss-sysinit` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.28.4-4.el6_9 | | `nss-tools` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.28.4-4.el6_9 | | `nss` | Red Hat:enterprise_linux:6::server | All versions | 0:3.28.4-4.el6_9 | | `nss-debuginfo` | Red Hat:enterprise_linux:6::server | All versions | 0:3.28.4-4.el6_9 | | `nss-devel` | Red Hat:enterprise_linux:6::server | All versions | 0:3.28.4-4.el6_9 | | `nss-pkcs11-devel` | Red Hat:enterprise_linux:6::server | All versions | 0:3.28.4-4.el6_9 | | `nss-sysinit` | Red Hat:enterprise_linux:6::server | All versions | 0:3.28.4-4.el6_9 | | `nss-tools` | Red Hat:enterprise_linux:6::server | All versions | 0:3.28.4-4.el6_9 | | `nss` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.28.4-4.el6_9 | | `nss-debuginfo` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.28.4-4.el6_9 | | `nss-devel` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.28.4-4.el6_9 | | `nss-pkcs11-devel` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.28.4-4.el6_9 | | `nss-sysinit` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.28.4-4.el6_9 | | `nss-tools` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.28.4-4.el6_9 | | `nss` | Red Hat:enterprise_linux:7::client | All versions | 0:3.28.4-12.el7_4 | | `nss-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:3.28.4-12.el7_4 | | `nss-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:3.28.4-12.el7_4 | | `nss-pkcs11-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:3.28.4-12.el7_4 | | `nss-sysinit` | Red Hat:enterprise_linux:7::client | All versions | 0:3.28.4-12.el7_4 | | `nss-tools` | Red Hat:enterprise_linux:7::client | All versions | 0:3.28.4-12.el7_4 | | `nss` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.28.4-12.el7_4 | | `nss-debuginfo` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.28.4-12.el7_4 | | `nss-devel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.28.4-12.el7_4 | | `nss-pkcs11-devel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.28.4-12.el7_4 | | `nss-sysinit` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.28.4-12.el7_4 | | `nss-tools` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.28.4-12.el7_4 | | `nss` | Red Hat:enterprise_linux:7::server | All versions | 0:3.28.4-12.el7_4 | | `nss-debuginfo` | Red Hat:enterprise_linux:7::server | All versions | 0:3.28.4-12.el7_4 | | `nss-devel` | Red Hat:enterprise_linux:7::server | All versions | 0:3.28.4-12.el7_4 | | `nss-pkcs11-devel` | Red Hat:enterprise_linux:7::server | All versions | 0:3.28.4-12.el7_4 | Products: Debian Debian Linux, Mozilla Firefox, Mozilla Thunderbird. ## How do I fix CVE-2017-7805? Upgrade to a fixed version. ## Is CVE-2017-7805 being exploited? There is no known exploitation of CVE-2017-7805 in the wild and no public exploit code. ## Other vulnerabilities in Debian Debian Linux - [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild) - [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild) - [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild) - [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild) - [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2017-7805 and fix it if it is affected. What it is: CVE-2017-7805 is a high-severity use after free vulnerability in Debian Debian Linux, published on 11 Jun 2018. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2017-7805 in the wild and no public exploit code. Affected product: Debian Debian 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-2017-7805/ (Markdown: https://insights.sbomify.com/CVE-2017-7805/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2017-7805 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-7805 - OSV: https://osv.dev/vulnerability/CVE-2017-7805 --- From sbomify Insights: https://insights.sbomify.com/CVE-2017-7805/ Summaries are generated and may contain mistakes; the official description above is the record.