Improper input validation in Cryptography Python-Cryptography
CVE-2018-10903
A flaw was found in python-cryptography versions between >=1.9.0 and <2.3. The finalize_with_tag API did not enforce a minimum tag length. If a user did not validate the input length prior to passing it to finalize_with_tag an attacker could craft an invalid payload with a shortened tag (e.g. 1 byte) such that they would have a 1 in 256 chance of passing the MAC check. GCM tag forgeries can cause key leakage.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.032 (87.7th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 88th percentile — 87.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.032 · newest: 0.032 · change: 0.000
Affected products
- Cryptography Python-Cryptography
- [Unknown] Python-Cryptography — versions 2.3
- Canonical Ubuntu Linux — versions 18.04
- Red Hat OpenStack — versions 13
Weakness classification (CWE)
Public proof-of-concept exploits
References
- access.redhat.com/errata/RHSA-2018:3600 (vendor-advisory)
- usn.ubuntu.com/3720-1/ (vendor-advisory, Third Party Advisory)
- bugzilla.redhat.com/show_bug.cgi (Patch, Third Party Advisory, Issue Tracking)
- github.com/pyca/cryptography/pull/4342/commits/688e0f673bfbf43fa898994326c6877f… (Patch, Third Party Advisory)
Frequently asked questions
- What is CVE-2018-10903?
- CVE-2018-10903 is a high-severity vulnerability in Cryptography Python-Cryptography, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2018-07-30.
- How severe is CVE-2018-10903?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2018-10903 known to be exploited?
- 5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.