# CVE-2020-2035: PAN-OS: URL filtering policy is not enforced on TLS handshakes for decrypted HTTPS sessions > Attackers can bypass URL filtering on decrypted HTTPS traffic by omitting SNI, allowing compromised hosts to evade security policies. - **Severity:** Low 3.0 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:L/A:N`) - **Exploited in the wild:** Not known - **Login needed:** An administrator - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** No - **Published:** 12 Aug 2020 - **Updated:** 17 Sep 2024 - **Also known as:** GHSA-j3cp-2wgv-xj2j ## What is CVE-2020-2035? CVE-2020-2035 is a low-severity vulnerability in Paloaltonetworks Pan-Os, published on 12 Aug 2020. An attacker needs administrator access to exploit it, with no action from the victim. ### Official description When SSL/TLS Forward Proxy Decryption mode has been configured to decrypt the web transactions, the PAN-OS URL filtering feature inspects the HTTP Host and URL path headers for policy enforcement on the decrypted HTTPS web transactions but does not consider Server Name Indication (SNI) field within the TLS Client Hello handshake. This allows a compromised host in a protected network to evade any security policy that uses URL filtering on a firewall configured with SSL Decryption in the Forward Proxy mode. A malicious actor can then use this technique to evade detection of communication on the TLS handshake phase between a compromised host and a remote malicious server. This technique does not increase the risk of a host being compromised in the network. It does not impact the confidentiality or availability of a firewall. This is considered to have a low impact on the integrity of the firewall because the firewall fails to enforce a policy on certain traffic that should have been blocked. This issue does not impact the URL filtering policy enforcement on clear text or encrypted web transactions. This technique can be used only after a malicious actor has compromised a host in the protected network and the TLS/SSL Decryption feature is enabled for the traffic that the attacker controls. Palo Alto Networks is not aware of any malware that uses this technique to exfiltrate data. This issue is applicable to all current versions of PAN-OS. This issue does not impact Panorama or WF-500 appliances. Weakness: CWE-20 (Improper Input Validation) ## Which versions are affected by CVE-2020-2035? It affects 1 product. Products: Paloaltonetworks Pan-Os. ## How do I fix CVE-2020-2035? No fix has been published for CVE-2020-2035 yet. Limit exposure of the affected software until one is available. ## Is CVE-2020-2035 being exploited? There is no known exploitation of CVE-2020-2035 in the wild and no public exploit code. ## Other vulnerabilities in Paloaltonetworks Pan-Os - [CVE-2024-3400](https://insights.sbomify.com/CVE-2024-3400/): Palo Alto Networks PAN-OS Command Injection (critical 10.0, exploited in the wild) - [CVE-2020-2021](https://insights.sbomify.com/CVE-2020-2021/): Palo Alto Networks PAN-OS Authentication Bypass (critical 10.0, exploited in the wild) - [CVE-2017-15944](https://insights.sbomify.com/CVE-2017-15944/): Palo Alto Networks PAN-OS Remote Code Execution (critical 9.8, exploited in the wild) - [CVE-2026-0300](https://insights.sbomify.com/CVE-2026-0300/): Palo Alto Networks PAN-OS Out-of-bounds Write (critical 9.3, exploited in the wild) - [CVE-2024-0012](https://insights.sbomify.com/CVE-2024-0012/): Palo Alto Networks PAN-OS Management Interface Authentication Bypass (critical 9.3, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2020-2035 and fix it if it is affected. What it is: CVE-2020-2035 is a low-severity vulnerability in Paloaltonetworks Pan-Os, published on 12 Aug 2020. An attacker needs administrator access to exploit it, with no action from the victim. Exploitation: There is no known exploitation of CVE-2020-2035 in the wild and no public exploit code. Affected product: Paloaltonetworks Pan-Os. 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-2020-2035/ (Markdown: https://insights.sbomify.com/CVE-2020-2035/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2020-2035 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-2035 - OSV: https://osv.dev/vulnerability/CVE-2020-2035 --- From sbomify Insights: https://insights.sbomify.com/CVE-2020-2035/ Summaries are generated and may contain mistakes; the official description above is the record.