# CVE-2017-7502: Null dereference in nss > Remote attackers can cause a denial of service in applications using NSS by sending empty SSLv2 messages, triggering a null pointer dereference. - **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:** 30 May 2017 - **Updated:** 5 Aug 2024 - **Also known as:** AZL-110498, DEBIAN-CVE-2017-7502, DLA-971-1, GHSA-97vv-2xv8-266j, MGASA-2017-0160, RHSA-2017:1364, RHSA-2017:1365, UBUNTU-CVE-2017-7502, USN-3336-1 ## What is CVE-2017-7502? CVE-2017-7502 is a high-severity vulnerability in Mozilla Network Security Services, published on 30 May 2017. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description Null pointer dereference vulnerability in NSS since 3.24.0 was found when server receives empty SSLv2 messages resulting into denial of service by remote attacker. Weakness: CWE-476 (NULL Pointer Dereference) ## Which versions are affected by CVE-2017-7502? It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `nss` | Red Hat:enterprise_linux:6::client | All versions | 0:3.28.4-3.el6_9 | | `nss-debuginfo` | Red Hat:enterprise_linux:6::client | All versions | 0:3.28.4-3.el6_9 | | `nss-devel` | Red Hat:enterprise_linux:6::client | All versions | 0:3.28.4-3.el6_9 | | `nss-pkcs11-devel` | Red Hat:enterprise_linux:6::client | All versions | 0:3.28.4-3.el6_9 | | `nss-sysinit` | Red Hat:enterprise_linux:6::client | All versions | 0:3.28.4-3.el6_9 | | `nss-tools` | Red Hat:enterprise_linux:6::client | All versions | 0:3.28.4-3.el6_9 | | `nss` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.28.4-3.el6_9 | | `nss-debuginfo` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.28.4-3.el6_9 | | `nss-devel` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.28.4-3.el6_9 | | `nss-pkcs11-devel` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.28.4-3.el6_9 | | `nss-sysinit` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.28.4-3.el6_9 | | `nss-tools` | Red Hat:enterprise_linux:6::computenode | All versions | 0:3.28.4-3.el6_9 | | `nss` | Red Hat:enterprise_linux:6::server | All versions | 0:3.28.4-3.el6_9 | | `nss-debuginfo` | Red Hat:enterprise_linux:6::server | All versions | 0:3.28.4-3.el6_9 | | `nss-devel` | Red Hat:enterprise_linux:6::server | All versions | 0:3.28.4-3.el6_9 | | `nss-pkcs11-devel` | Red Hat:enterprise_linux:6::server | All versions | 0:3.28.4-3.el6_9 | | `nss-sysinit` | Red Hat:enterprise_linux:6::server | All versions | 0:3.28.4-3.el6_9 | | `nss-tools` | Red Hat:enterprise_linux:6::server | All versions | 0:3.28.4-3.el6_9 | | `nss` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.28.4-3.el6_9 | | `nss-debuginfo` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.28.4-3.el6_9 | | `nss-devel` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.28.4-3.el6_9 | | `nss-pkcs11-devel` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.28.4-3.el6_9 | | `nss-sysinit` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.28.4-3.el6_9 | | `nss-tools` | Red Hat:enterprise_linux:6::workstation | All versions | 0:3.28.4-3.el6_9 | | `nss` | Red Hat:enterprise_linux:7::client | All versions | 0:3.28.4-1.2.el7_3 | | `nss-debuginfo` | Red Hat:enterprise_linux:7::client | All versions | 0:3.28.4-1.2.el7_3 | | `nss-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:3.28.4-1.2.el7_3 | | `nss-pkcs11-devel` | Red Hat:enterprise_linux:7::client | All versions | 0:3.28.4-1.2.el7_3 | | `nss-sysinit` | Red Hat:enterprise_linux:7::client | All versions | 0:3.28.4-1.2.el7_3 | | `nss-tools` | Red Hat:enterprise_linux:7::client | All versions | 0:3.28.4-1.2.el7_3 | | `nss` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.28.4-1.2.el7_3 | | `nss-debuginfo` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.28.4-1.2.el7_3 | | `nss-devel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.28.4-1.2.el7_3 | | `nss-pkcs11-devel` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.28.4-1.2.el7_3 | | `nss-sysinit` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.28.4-1.2.el7_3 | | `nss-tools` | Red Hat:enterprise_linux:7::computenode | All versions | 0:3.28.4-1.2.el7_3 | | `nss` | Red Hat:enterprise_linux:7::server | All versions | 0:3.28.4-1.2.el7_3 | | `nss-debuginfo` | Red Hat:enterprise_linux:7::server | All versions | 0:3.28.4-1.2.el7_3 | | `nss-devel` | Red Hat:enterprise_linux:7::server | All versions | 0:3.28.4-1.2.el7_3 | | `nss-pkcs11-devel` | Red Hat:enterprise_linux:7::server | All versions | 0:3.28.4-1.2.el7_3 | Products: Mozilla Network Security Services. ## How do I fix CVE-2017-7502? Apply the vendor's patch. ## Is CVE-2017-7502 being exploited? There is no known exploitation of CVE-2017-7502 in the wild and no public exploit code. ## Other vulnerabilities in Mozilla Network Security Services - [CVE-2019-17006](https://insights.sbomify.com/CVE-2019-17006/): Memory corruption in NSS (critical 9.8) - [CVE-2017-5461](https://insights.sbomify.com/CVE-2017-5461/): Memory corruption in Firefox (critical 9.8) - [CVE-2009-2404](https://insights.sbomify.com/CVE-2009-2404/): Memory corruption in n/a (critical 9.3) - [CVE-2017-11695](https://insights.sbomify.com/CVE-2017-11695/): Memory corruption in n/a (high 7.8) - [CVE-2017-11696](https://insights.sbomify.com/CVE-2017-11696/): Memory corruption in n/a (high 7.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2017-7502 and fix it if it is affected. What it is: CVE-2017-7502 is a high-severity vulnerability in Mozilla Network Security Services, published on 30 May 2017. 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-2017-7502 in the wild and no public exploit code. Affected product: Mozilla Network Security Services. 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-2017-7502/ (Markdown: https://insights.sbomify.com/CVE-2017-7502/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2017-7502 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-7502 - OSV: https://osv.dev/vulnerability/CVE-2017-7502 --- From sbomify Insights: https://insights.sbomify.com/CVE-2017-7502/ Summaries are generated and may contain mistakes; the official description above is the record.