CVE-2021-28899Network attack vector

Unauthenticated RTSP server crash

Published Apr 29, 2021 · Updated Aug 3, 2024

Implementation flaw in LIVE555 Streaming Media before 2021.3.16 allows remote attackers to crash affected RTSP servers. OnDemandServerMediaSubsession mishandles malicious RTSP client input in the AC3, ADTS, and AMR audio file subclasses, but the upstream notice does not disclose the erroneous operation. Exposure is limited to RTSP servers using those subclasses; the DynamicRTSPServer used by LIVE555 Media Server is explicitly unaffected.

CVSS severity7.5
High
EPSS probability1.09%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Implementation flaw in LIVE555 Streaming Media before 2021.3.16 allows remote attackers to crash affected RTSP servers. OnDemandServerMediaSubsession mishandles malicious RTSP client input in the AC3, ADTS, and AMR audio file subclasses, but the upstream notice does not disclose the erroneous operation. Exposure is limited to RTSP servers using those subclasses; the DynamicRTSPServer used by LIVE555 Media Server is explicitly unaffected.

The record

CVE
CVE-2021-28899
Published
Apr 29, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 29, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.0NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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