BugZero | Cisco BugID CSCwe45287 - When using SRTP with higher ciphers, CUBE is inser...

Cisco - Defect ID: CSCwe45287

When using SRTP with higher ciphers, CUBE is inserting distortion in voice

Cisco - Defect ID: CSCwe45287

When using SRTP with higher ciphers, CUBE is inserting distortion in voice

Last updated on December 21st, 2025

BugZero Risk Score
6.0 Medium

Overall: 6.0

Severity: 6.4

Lifecycle: 9.1

Popularity: 3.7

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Bug Details

Views: 2

Description

Symptom

When using SRTP with higher ciphers, CUBE is inserting distortion in voice. Only if customer disables higher ciphers from the CUBE by using srtp-crypto voice class commands the audio issue does not happen. It seems CUBE is unable to handle properly higher ciphers during SRTP, which is causing audio to get distorted.

Conditions

Issue is not happening if the customer uses "lower" ciphers in the CUBE, only appers when customer uses higher ciphers like (AEAD_AES_256_GCM)

Workaround

(To stop the CUBE from negotiating higher ciphers, the following workaround was suggested) voice class srtp-crypto 100 crypto 1 AES_CM_128_HMAC_SHA1_32 crypto 2 AES_CM_128_HMAC_SHA1_80 ! voice service voip sip srtp-crypto 100

Further Problem Description

Issue has been experienced by the customer using 16.12.04, 16.12.06 and 17.3.5. Other versions have not been tested. Call flow: User 1 --> PSTN --> RTP --> CUBE#1 --> SRTP --> CUBE#2 --> RTP --> PSTN --> IVR In this scenario, customer is calling an IVR, voice is coming with no distortion from PSTN to CUBE#2, however, when CUBE#2 encrypts the audio and sends it to CUBE#1 using SRTP, the audio is getting distorted if CUBE#2 uses higher ciphers like AEAD_AES_256_GCM to encrypt the RTP.

Change history

2025-12-21 Added: 17.12.5c, 17.12.5d, 17.12.6, 17.12.6a, 17.15.1z, 17.15.4, 17.15.4a, 17.15.4b, 17.15.4c, 17.15.4d, 17.15.4s1, 17.18.1, 17.18.1a, 17.18.1w, 17.9.8

2025-12-02 Added: 17.12.5c, 17.12.5d, 17.12.6, 17.12.6a, 17.15.1z, 17.15.4, 17.15.4a, 17.15.4b, 17.15.4c, 17.15.4s1, 17.18.1, 17.18.1a, 17.18.1w, 17.9.8

2025-11-10 Added: 17.12.5c, 17.12.5d, 17.12.6, 17.12.6a, 17.15.1z, 17.15.4, 17.15.4a, 17.15.4b, 17.15.4c, 17.15.4s1, 17.18.1, 17.18.1a, 17.9.8

2025-11-03 Added: 17.12.5c, 17.12.5d, 17.12.6, 17.12.6a, 17.15.1z, 17.15.4, 17.15.4a, 17.15.4b, 17.15.4c, 17.18.1, 17.18.1a, 17.9.8

2025-10-09 Added: 17.12.5c, 17.12.6, 17.12.6a, 17.15.1z, 17.15.4, 17.15.4a, 17.15.4b, 17.15.4c, 17.18.1, 17.18.1a, 17.9.8

2025-10-01 Added: 17.12.5c, 17.12.6, 17.12.6a, 17.15.1z, 17.15.4, 17.15.4a, 17.15.4b, 17.15.4c, 17.18.1, 17.18.1a

2025-09-22 Added: 17.12.5c, 17.12.6, 17.15.1z, 17.15.4, 17.15.4a, 17.15.4b, 17.18.1, 17.18.1a

2025-09-08 Added: 17.12.6, 17.15.4, 17.15.4a, 17.18.1, 17.18.1a

2025-08-25 Added: 17.15.4, 17.15.4a, 17.18.1, 17.18.1a

2025-08-18 Added: 17.15.4, 17.15.4a

2025-07-07 Added: 17.12.02a, 17.12.1, 17.12.1a, 17.12.1w, 17.12.1x, 17.12.1y, 17.12.1z, 17.12.1z1, 17.12.1z2, 17.12.1z3, 17.12.1z4, 17.12.2, 17.12.2a, 17.12.3, 17.12.3a, 17.12.4, 17.12.4a, 17.12.4b, 17.12.5, 17.12.5a, 17.12.5b, 17.13.1, 17.13.1a, 17.14.1, 17.14.1a, 17.15.1, 17.15.1a, 17.15.1b, 17.15.1w, 17.15.1x, 17.15.1y, 17.15.2, 17.15.2a, 17.15.2b, 17.15.2c, 17.15.3, 17.15.3a, 17.15.3b, 17.16.1, 17.16.1a, 17.17.1, 17.6.5, 17.6.5a, 17.6.6, 17.6.6a, 17.6.7, 17.6.8, 17.6.8a, 17.9.4, 17.9.4a, 17.9.5, 17.9.5a, 17.9.5b, 17.9.5c, 17.9.5d, 17.9.5e, 17.9.5f, 17.9.6, 17.9.6a, 17.9.6b, 17.9.7, 17.9.7a, 17.9.7b

Relevant Products

Click on a version to see all relevant bugs

Affected versions:No known affected versions

Fixed versions: 17.12.02a, 17.12.1, 17.12.1a, 17.12.1w, 17.12.1x, 17.12.1y, 17.12.1z, 17.12.1z1, 17.12.1z2, 17.12.1z3, 17.12.1z4, 17.12.2, 17.12.2a, 17.12.3, 17.12.3a, 17.12.4, 17.12.4a, 17.12.4b, 17.12.5, 17.12.5a, 17.12.5b, 17.12.5c, 17.12.5d, 17.12.6, 17.12.6a, 17.13.1, 17.13.1a, 17.14.1, 17.14.1a, 17.15.1, 17.15.1a, 17.15.1b, 17.15.1w, 17.15.1x, 17.15.1y, 17.15.1z, 17.15.2, 17.15.2a, 17.15.2b, 17.15.2c, 17.15.3, 17.15.3a, 17.15.3b, 17.15.4, 17.15.4a, 17.15.4b, 17.15.4c, 17.15.4d, 17.15.4s1, 17.16.1, 17.16.1a, 17.17.1, 17.18.1, 17.18.1a, 17.18.1w, 17.6.5, 17.6.5a, 17.6.6, 17.6.6a, 17.6.7, 17.6.8, 17.6.8a, 17.9.4, 17.9.4a, 17.9.5, 17.9.5a, 17.9.5b, 17.9.5c, 17.9.5d, 17.9.5e, 17.9.5f, 17.9.6, 17.9.6a, 17.9.6b, 17.9.7, 17.9.7a, 17.9.7b, 17.9.8

Relevant Products

Click on a version to see all relevant bugs

Affected versions:No known affected versions

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Cisco - Defect ID: CSCwe45287

When using SRTP with higher ciphers, CUBE is inserting distortion in voice

Cisco - Defect ID: CSCwe45287

When using SRTP with higher ciphers, CUBE is inserting distortion in voice

Last updated on December 21st, 2025

BugZero Risk Score6.0 Medium

Bug Details

Symptom

Conditions

Workaround

Further Problem Description

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BugZero Risk Score
6.0 Medium