CVE-2016-9243
high
CVSS v3
7.5
CVSS v4 NEW
—
VIR risk
7.5
Description
HKDF in cryptography before 1.5.2 returns an empty byte-string if used with a length less than algorithm.digest_size.
Predictions
Exploit likelihood
83%
Patch ETA
—
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
Fedora Affected 3 releases
| Version | Status | Fixed in |
|---|---|---|
| 25 | Affected | — |
| 24 | Affected | — |
| 23 | Affected | — |
Ubuntu Affected 2 releases
| Version | Status | Fixed in |
|---|---|---|
| 16.10 | Affected | — |
| 16.04 | Affected | — |
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 1.5.3-1 |
| sid | Fixed | 1.5.3-1 |
| forky | Fixed | 1.5.3-1 |
| bullseye | Fixed | 1.5.3-1 |
| bookworm | Fixed | 1.5.3-1 |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| PyPI | cryptography | <1.5.3 | 1.5.3 |
| PyPI | cryptography | <b924696b2e8731f39696584d12cceeb3aeb2d874||<1.5.3 | b924696b2e8731f39696584d12cceeb3aeb2d874 |
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| cryptography.io | cryptography | {"endIncluding":"1.5.2"} | |
References
- http://www.openwall.com/lists/oss-security/2016/11/09/2
- http://www.securityfocus.com/bid/94216
- http://www.ubuntu.com/usn/USN-3138-1
- https://cryptography.io/en/latest/changelog
- https://github.com/pyca/cryptography/commit/b924696b2e8731f39696584d12cceeb3aeb2d874
- https://github.com/pyca/cryptography/issues/3211
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5R2ZOBMPWDFFHUZ6QOZZY36A6H5CGJXL/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U23KDR2M2N7W2ZSREG63BVW7D4VC6CIZ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WQ5G7KHKZC4SI23JE7277KZXM57GEQKT/
- https://nvd.nist.gov/vuln/detail/CVE-2016-9243
- https://cryptography.io/en/latest/changelog/#v1-5-3
- https://github.com/advisories/GHSA-q3cj-2r34-2cwc
- https://github.com/pyca/cryptography
- https://github.com/pypa/advisory-database/tree/main/vulns/cryptography/PYSEC-2017-8.yaml
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5R2ZOBMPWDFFHUZ6QOZZY36A6H5CGJXL
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U23KDR2M2N7W2ZSREG63BVW7D4VC6CIZ
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WQ5G7KHKZC4SI23JE7277KZXM57GEQKT
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5R2ZOBMPWDFFHUZ6QOZZY36A6H5CGJXL
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/U23KDR2M2N7W2ZSREG63BVW7D4VC6CIZ
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WQ5G7KHKZC4SI23JE7277KZXM57GEQKT
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WQ5G7KHKZC4SI23JE7277KZXM57GEQKT/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/U23KDR2M2N7W2ZSREG63BVW7D4VC6CIZ/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5R2ZOBMPWDFFHUZ6QOZZY36A6H5CGJXL/
- https://security-tracker.debian.org/tracker/CVE-2016-9243
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.