CVE-2013-1895
Improper Restriction of Excessive Authentication Attempts in py-bcrypt
The py-bcrypt module before 0.3 for Python does not properly handle concurrent memory access, which allows attackers to bypass authentication via multiple authentication requests, which trigger the password hash to be overwritten.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
The py-bcrypt module before 0.3 for Python does not properly handle concurrent memory access, which allows attackers to bypass authentication via multiple authentication requests, which trigger the password hash to be overwritten.
- Record
CVE-2013-1895- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:P/A:N - Weakness
- CWE-307
- Updated
- 2026-11-02
CVE List No score
The py-bcrypt module before 0.3 for Python does not properly handle concurrent memory access, which allows attackers to bypass authentication via multiple authentication requests, which trigger the password hash to be overwritten.
- Record
CVE-2013-1895- Updated
- 2026-11-02
EUVDEUVD-2020-0151 No score
The py-bcrypt module before 0.3 for Python does not properly handle concurrent memory access, which allows attackers to bypass authentication via multiple authentication requests, which trigger the password hash to be overwritten.
- Record
EUVD-2020-0151- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-r838-q6jp-58xx
Improper Restriction of Excessive Authentication Attempts in py-bcrypt
The py-bcrypt module before 0.3 for Python does not properly handle concurrent memory access, which allows attackers to bypass authentication via multiple authentication requests, which trigger the password hash to be overwritten.
- Record
GHSA-r838-q6jp-58xx- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-307
- Updated
- 2026-11-02
OSV
The py-bcrypt module before 0.3 for Python does not properly handle concurrent memory access, which allows attackers to bypass authentication via multiple authentication requests, which trigger the password hash to be overwritten.
- Record
CVE-2013-1895- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
OSVDEBIAN-CVE-2013-1895
The py-bcrypt module before 0.3 for Python does not properly handle concurrent memory access, which allows attackers to bypass authentication via multiple authentication requests, which trigger the password hash to be overwritten.
- Record
DEBIAN-CVE-2013-1895- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
OSVGHSA-r838-q6jp-58xx
Improper Restriction of Excessive Authentication Attempts in py-bcrypt
The py-bcrypt module before 0.3 for Python does not properly handle concurrent memory access, which allows attackers to bypass authentication via multiple authentication requests, which trigger the password hash to be overwritten.
- Record
GHSA-r838-q6jp-58xx- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Weakness
- CWE-307
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2013-1895
The py-bcrypt module before 0.3 for Python does not properly handle concurrent memory access, which allows attackers to bypass authentication via multiple authentication requests, which trigger the password hash to be overwritten.
- Record
UBUNTU-CVE-2013-1895- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - Updated
- 2026-11-02
OSVPYSEC-2020-249 No score
The py-bcrypt module before 0.3 for Python does not properly handle concurrent memory access, which allows attackers to bypass authentication via multiple authentication requests, which trigger the password hash to be overwritten.
- Record
PYSEC-2020-249- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
py-bcryptPyPI |
before 0.3 | 0.3 |
python-bcryptDebian:12 |
before 0.4-1 | 0.4-1 |
python-bcryptDebian:13 |
before 0.4-1 | 0.4-1 |
python-bcryptDebian:14 |
before 0.4-1 | 0.4-1 |
py-bcryptPyPI |
before 0.3, plus listed versions 0.10.2 |
0.3 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected | ||
| 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-2013-1895 is a high vulnerability (CVSS 7.5) in Py-bcrypt, published January 28, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.83%, the 86th percentile. Fixed in py-bcrypt 0.3.
References
openwall.com/lists/oss-security/2013/03/26/2
lists.fedoraproject.org/pipermail/package-announce/2013-April/101387.html
securityfocus.com/bid/58702
exchange.xforce.ibmcloud.com/vulnerabilities/83039
nvd.nist.gov/vuln/detail/CVE-2013-1895