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Mallory
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Arbitrary Code Execution via Malicious Webex Recording Files

IdentifiersCVE-2021-1503CWE-20

CVE-2021-1503 is a vulnerability in Cisco Webex Network Recording Player and Cisco Webex Player for both Windows and MacOS. The vulnerability arises from insufficient validation of values within ARF and WRF Webex recording files. An attacker can craft a malicious ARF or WRF file and deliver it to a target, who, upon opening the file with the vulnerable player, triggers arbitrary code execution with the privileges of the user.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows an attacker to execute arbitrary code on the victim's system with the privileges of the user who opens the malicious recording file. This can lead to full compromise of the affected system, including installation of malware, data theft, or lateral movement within a network.

Mitigation

If you can’t patch tonight, do this now.

Do not open ARF or WRF files from untrusted or unknown sources. Employ endpoint security solutions that can detect and block malicious files. Consider restricting the use of Webex Player to trusted users and environments until patched.

Remediation

Patch, then assume compromise.

Upgrade Cisco Webex Network Recording Player and Cisco Webex Player to the latest versions provided by Cisco that address this vulnerability. Cisco has released software updates that properly validate ARF and WRF file contents.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
Cisco SystemsWebex Meetings Serverapplication
Cisco SystemsWebex Playerapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity

Community discussion across Reddit, Mastodon, and other social sources.