CVE-2021-3177
Published: 19 January 2021
Python 3.x through 3.9.1 has a buffer overflow in PyCArg_repr in _ctypes/callproc.c, which may lead to remote code execution in certain Python applications that accept floating-point numbers as untrusted input, as demonstrated by a 1e300 argument to c_double.from_param. This occurs because sprintf is used unsafely.
Notes
| Author | Note |
|---|---|
| mdeslaur | on Ubuntu, binaries are compiled with Fortify Source, so exploiting this issue will likely only cause Python to crash, leading to a denial of service. |
Priority
Status
| Package | Release | Status |
|---|---|---|
|
python2.7 Launchpad, Ubuntu, Debian |
bionic |
Released
(2.7.17-1~18.04ubuntu1.6)
|
| focal |
Released
(2.7.18-1~20.04.1)
|
|
| groovy |
Ignored
(reached end-of-life)
|
|
| hirsute |
Not vulnerable
(2.7.18-4)
|
|
| impish |
Not vulnerable
(2.7.18-4)
|
|
| jammy |
Not vulnerable
(2.7.18-4)
|
|
| kinetic |
Not vulnerable
(2.7.18-4)
|
|
| precise |
Ignored
|
|
| trusty |
Released
(2.7.6-8ubuntu0.6+esm10)
|
|
| upstream |
Needs triage
|
|
| xenial |
Released
(2.7.12-1ubuntu0~16.04.18)
|
|
| This vulnerability is mitigated in part by the use of -D_FORTIFY_SOURCE=2 in Ubuntu. | ||
|
python3.4 Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
| focal |
Does not exist
|
|
| groovy |
Does not exist
|
|
| hirsute |
Does not exist
|
|
| impish |
Does not exist
|
|
| jammy |
Does not exist
|
|
| kinetic |
Does not exist
|
|
| precise |
Does not exist
|
|
| trusty |
Released
(3.4.3-1ubuntu1~14.04.7+esm10)
|
|
| upstream |
Needs triage
|
|
| xenial |
Does not exist
|
|
| This vulnerability is mitigated in part by the use of -D_FORTIFY_SOURCE=2 in Ubuntu. | ||
|
python3.5 Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
| focal |
Does not exist
|
|
| groovy |
Does not exist
|
|
| hirsute |
Does not exist
|
|
| impish |
Does not exist
|
|
| jammy |
Does not exist
|
|
| kinetic |
Does not exist
|
|
| precise |
Does not exist
|
|
| trusty |
Needs triage
|
|
| upstream |
Needs triage
|
|
| xenial |
Released
(3.5.2-2ubuntu0~16.04.13)
|
|
| This vulnerability is mitigated in part by the use of -D_FORTIFY_SOURCE=2 in Ubuntu. | ||
|
python3.6 Launchpad, Ubuntu, Debian |
bionic |
Released
(3.6.9-1~18.04ubuntu1.4)
|
| focal |
Does not exist
|
|
| groovy |
Does not exist
|
|
| hirsute |
Does not exist
|
|
| impish |
Does not exist
|
|
| jammy |
Does not exist
|
|
| kinetic |
Does not exist
|
|
| precise |
Does not exist
|
|
| trusty |
Does not exist
|
|
| upstream |
Needs triage
|
|
| xenial |
Does not exist
|
|
|
Patches: upstream: https://github.com/python/cpython/commit/34df10a9a16b38d54421eeeaf73ec89828563be7 (3.6) |
||
| This vulnerability is mitigated in part by the use of -D_FORTIFY_SOURCE=2 in Ubuntu. | ||
|
python3.7 Launchpad, Ubuntu, Debian |
bionic |
Released
(3.7.5-2~18.04.4)
|
| focal |
Does not exist
|
|
| groovy |
Does not exist
|
|
| hirsute |
Does not exist
|
|
| impish |
Does not exist
|
|
| jammy |
Does not exist
|
|
| kinetic |
Does not exist
|
|
| precise |
Does not exist
|
|
| trusty |
Does not exist
|
|
| upstream |
Needs triage
|
|
| xenial |
Does not exist
|
|
|
Patches: upstream: https://github.com/python/cpython/commit/d9b8f138b7df3b455b54653ca59f491b4840d6fa (3.7) |
||
|
python3.8 Launchpad, Ubuntu, Debian |
bionic |
Released
(3.8.0-3~18.04.1)
|
| focal |
Released
(3.8.5-1~20.04.2)
|
|
| groovy |
Released
(3.8.6-1ubuntu0.2)
|
|
| hirsute |
Does not exist
|
|
| impish |
Does not exist
|
|
| jammy |
Does not exist
|
|
| kinetic |
Does not exist
|
|
| precise |
Does not exist
|
|
| trusty |
Does not exist
|
|
| upstream |
Needs triage
|
|
| xenial |
Does not exist
|
|
|
Patches: upstream: https://github.com/python/cpython/commit/ece5dfd403dac211f8d3c72701fe7ba7b7aa5b5f (3.8) |
||
| This vulnerability is mitigated in part by the use of -D_FORTIFY_SOURCE=2 in Ubuntu. | ||
|
python3.9 Launchpad, Ubuntu, Debian |
bionic |
Does not exist
|
| focal |
Released
(3.9.5-3~20.04.1)
|
|
| groovy |
Released
(3.9.5-3~20.10.1)
|
|
| hirsute |
Not vulnerable
(3.9.1-3)
|
|
| impish |
Not vulnerable
(3.9.1-3)
|
|
| jammy |
Does not exist
|
|
| kinetic |
Does not exist
|
|
| precise |
Does not exist
|
|
| trusty |
Does not exist
|
|
| upstream |
Released
(3.9.1-3)
|
|
| xenial |
Does not exist
|
|
|
Patches: upstream: https://github.com/python/cpython/commit/c347cbe694743cee120457aa6626712f7799a932 (3.9) |
||
| This vulnerability is mitigated in part by the use of -D_FORTIFY_SOURCE=2 in Ubuntu. | ||
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 9.8 |
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | High |
| Availability impact | High |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
References
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3177
- https://bugs.python.org/issue42938
- https://github.com/python/cpython/pull/24239
- https://python-security.readthedocs.io/vuln/ctypes-buffer-overflow-pycarg_repr.html
- https://ubuntu.com/security/notices/USN-4754-1
- https://ubuntu.com/security/notices/USN-4754-2 (regression in python2.7)
- https://ubuntu.com/security/notices/USN-4754-4
- https://ubuntu.com/security/notices/USN-4754-3
- https://ubuntu.com/security/notices/USN-4754-5
- NVD
- Launchpad
- Debian