CVE-2021-37577
Bluetooth LE and BR/EDR Secure Connections pairing and Secure Simple Pairing using the Passkey...
Bluetooth LE and BR/EDR Secure Connections pairing and Secure Simple Pairing using the Passkey entry protocol in Bluetooth Core Specifications 2.1 through 5.3 may permit an unauthenticated man-in-the-middle attacker to identify the Passkey used during pairing by reflection of a crafted public key with the same X coordinate as the offered public key and by reflection of the authentication evidence of the initiating device, potentially permitting this attacker to complete authenticated pairing with the responding device using the correct Passkey for the pairing session. This is a related issue to CVE-2020-26558.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Bluetooth LE and BR/EDR Secure Connections pairing and Secure Simple Pairing using the Passkey entry protocol in Bluetooth Core Specifications 2.1 through 5.3 may permit an unauthenticated man-in-the-middle attacker to identify the Passkey used during pairing by reflection of a crafted public key with the same X coordinate as the offered public key and by reflection of the authentication evidence of the initiating device, potentially permitting this attacker to complete authenticated pairing with the responding device using the correct Passkey for the pairing session. This is a related issue to CVE-2020-26558.
- Record
CVE-2021-37577- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L - Weakness
- CWE-639
- Updated
- 2026-11-02
EUVDEUVD-2021-24138
Bluetooth LE and BR/EDR Secure Connections pairing and Secure Simple Pairing using the Passkey entry protocol in Bluetooth Core Specifications 2.1 through 5.3 may permit an unauthenticated man-in-the-middle attacker to identify the Passkey used during pairing by reflection of a crafted public key with the same X coordinate as the offered public key and by reflection of the authentication evidence of the initiating device, potentially permitting this attacker to complete authenticated pairing with the responding device using the correct Passkey for the pairing session. This is a related issue to CVE-2020-26558.
- Record
EUVD-2021-24138- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-f7h9-hrg7-94fg
Bluetooth LE and BR/EDR Secure Connections pairing and Secure Simple Pairing using the Passkey...
Bluetooth LE and BR/EDR Secure Connections pairing and Secure Simple Pairing using the Passkey entry protocol in Bluetooth Core Specifications 2.1 through 5.3 may permit an unauthenticated man-in-the-middle attacker to identify the Passkey used during pairing by reflection of a crafted public key with the same X coordinate as the offered public key and by reflection of the authentication evidence of the initiating device, potentially permitting this attacker to complete authenticated pairing with the responding device using the correct Passkey for the pairing session. This is a related issue to CVE-2020-26558.
- Record
GHSA-f7h9-hrg7-94fg- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L - Weakness
- CWE-639
- Updated
- 2026-11-02
NVD
Bluetooth LE and BR/EDR Secure Connections pairing and Secure Simple Pairing using the Passkey entry protocol in Bluetooth Core Specifications 2.1 through 5.3 may permit an unauthenticated man-in-the-middle attacker to identify the Passkey used during pairing by reflection of a crafted public key with the same X coordinate as the offered public key and by reflection of the authentication evidence of the initiating device, potentially permitting this attacker to complete authenticated pairing with the responding device using the correct Passkey for the pairing session. This is a related issue to CVE-2020-26558.
- Record
CVE-2021-37577- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L - Weakness
- CWE-639
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-37577
Bluetooth LE and BR/EDR Secure Connections pairing and Secure Simple Pairing using the Passkey entry protocol in Bluetooth Core Specifications 2.1 through 5.3 may permit an unauthenticated man-in-the-middle attacker to identify the Passkey used during pairing by reflection of a crafted public key with the same X coordinate as the offered public key and by reflection of the authentication evidence of the initiating device, potentially permitting this attacker to complete authenticated pairing with the responding device using the correct Passkey for the pairing session. This is a related issue to CVE-2020-26558.
- Record
UBUNTU-CVE-2021-37577- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:L - Updated
- 2026-11-02
Affected packages
| Package | Affected | Fixed |
|---|---|---|
bluezUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 5.35-0ubuntu25.36-0ubuntu15.37-0ubuntu55.37-0ubuntu5.15.37-0ubuntu5.3 Show 6 moreShow less5.37-0ubuntu5.3+esm15.37-0ubuntu5.3+esm25.37-0ubuntu5.3+esm35.37-0ubuntu5.3+esm45.37-0ubuntu5.3+esm55.37-0ubuntu5.3+esm6 |
None known |
bluezUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 5.46-0ubuntu35.46-0ubuntu45.48-0ubuntu35.48-0ubuntu3.15.48-0ubuntu3.2 Show 10 moreShow less5.48-0ubuntu3.35.48-0ubuntu3.45.48-0ubuntu3.55.48-0ubuntu3.65.48-0ubuntu3.75.48-0ubuntu3.85.48-0ubuntu3.95.48-0ubuntu3.9+esm15.48-0ubuntu3.9+esm25.48-0ubuntu3.9+esm3 |
None known |
bluezUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 5.50-0ubuntu45.51-0ubuntu15.51-0ubuntu25.52-0ubuntu15.52-0ubuntu2 Show 14 moreShow less5.53-0ubuntu15.53-0ubuntu25.53-0ubuntu35.53-0ubuntu3.15.53-0ubuntu3.25.53-0ubuntu3.35.53-0ubuntu3.45.53-0ubuntu3.55.53-0ubuntu3.65.53-0ubuntu3.75.53-0ubuntu3.85.53-0ubuntu3.95.53-0ubuntu3.9+esm15.53-0ubuntu3.9+esm2 |
None known |
bluezUbuntu:22.04:LTS |
All versions, plus listed versions 5.60-0ubuntu25.62-0ubuntu15.62-0ubuntu25.63-0ubuntu15.63-0ubuntu2 Show 6 moreShow less5.64-0ubuntu15.64-0ubuntu1.15.64-0ubuntu1.35.64-0ubuntu1.45.64-0ubuntu1.55.64-0ubuntu1.6 |
None known |
bluezUbuntu:24.04:LTS |
All versions, plus listed versions 5.68-0ubuntu15.70-0ubuntu15.70-0ubuntu25.70-0ubuntu35.71-0ubuntu3 Show 13 moreShow less5.71-1ubuntu25.71-1ubuntu35.72-0ubuntu15.72-0ubuntu35.72-0ubuntu45.72-0ubuntu55.72-0ubuntu5.15.72-0ubuntu5.35.72-0ubuntu5.45.72-0ubuntu5.55.72-0ubuntu5.65.72-0ubuntu5.75.72-0ubuntu5.8 |
None known |
bluezUbuntu:25.10 |
All versions, plus listed versions 5.79-2ubuntu15.82-15.82-1ubuntu15.83-1~exp15.83-1~exp1ubuntu0.1 |
None known |
bluezUbuntu:26.10 |
All versions, plus listed versions 5.85-45.85-4ubuntu15.87-15.87-25.87-35.87-4 |
None known |
bluezUbuntu:26.04:LTS |
All versions, plus listed versions 5.83-1~exp15.84-15.85-15.85-25.85-3 Show 5 moreShow less5.85-45.85-4ubuntu0.15.85-4ubuntu0.25.85-4ubuntu0.35.85-4ubuntu0.4 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-37577 is a medium vulnerability (CVSS 6.8) in bluez, published October 1, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.24%, the 15th percentile. No source names a fixed version.
References
bluetooth.com
bluetooth.com/learn-about-bluetooth/key-attributes/bluetooth-security/reporting-security
nvd.nist.gov/vuln/detail/CVE-2021-37577
github.com/advisories/GHSA-f7h9-hrg7-94fg
ubuntu.com/security/CVE-2021-37577
cve.org/CVERecord?id=CVE-2021-37577