What is the CVSS score of CVE-2018-20436?

CVE-2018-20436 has a CVSS 3.0 base score of 8.1 (High). CVSS vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 1.6%.

Is there a public PoC exploit available for CVE-2018-20436?

Yes, a public proof-of-concept exploit is available for CVE-2018-20436. Prioritise patching immediately. EPSS: 1.6%.

Web CVE-2018-20436

HIGH

Server-Side Request Forgery (SSRF) (CWE-918)

2018-12-24 cve@mitre.org

Google SSRF Web Telegram

8.1

CVSS 3.0 · NVD

Severity by source

NVD PRIMARY

8.1 HIGH

AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

CVE Published

Dec 24, 2018 - 20:29 nvd

HIGH 8.1

DescriptionNVD

The "secret chat" feature in Telegram 4.9.1 for Android has a "side channel" in which Telegram servers send GET requests for URLs typed while composing a chat message, before that chat message is sent. There are also GET requests to other URLs on the same web server. This also affects one or more other Telegram products, such as Telegram Web-version 0.7.0. In addition, it can be interpreted as an SSRF issue. NOTE: a third party has reported that potentially unwanted behavior is caused by misconfiguration of the "Secret chats > Preview links" setting

AnalysisAI

The "secret chat" feature in Telegram 4.9.1 for Android has a "side channel" in which Telegram servers send GET requests for URLs typed while composing a chat message, before that chat message is. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, no authentication required. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Server-Side Request Forgery (SSRF) (CWE-918), which allows attackers to make the server perform requests to unintended internal or external resources. The "secret chat" feature in Telegram 4.9.1 for Android has a "side channel" in which Telegram servers send GET requests for URLs typed while composing a chat message, before that chat message is sent. There are also GET requests to other URLs on the same web server. This also affects one or more other Telegram products, such as Telegram Web-version 0.7.0. In addition, it can be interpreted as an SSRF issue. NOTE: a third party has reported that potentially unwanted behavior is caused by misconfiguration of the "Secret chats > Preview links" setting Affected products include: Telegram, Telegram Web. Version information: version 0.7.0..

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Validate and allowlist destination URLs, block requests to internal networks, use network segmentation.