NULL pointer dereference in Opensmtpd
CVE-2020-35680
smtpd/lka_filter.c in OpenSMTPD before 6.8.0p1, in certain configurations, allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted pattern of client activity, because the filter state machine does not properly maintain the I/O channel between the SMTP engine and the filters layer.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.037 (89.5th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 89th percentile — 89.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.037 · newest: 0.037 · change: 0.000
Affected products
- Opensmtpd — versions 6.8.0
- Fedoraproject Fedora — versions 32, 33
Weakness classification (CWE)
Public proof-of-concept exploits
References
- poolp.org/posts/2020-12-24/december-2020-opensmtpd-6.8.0p1-released-fixed-sever… (Third Party Advisory)
- www.mail-archive.com/misc@opensmtpd.org/msg05188.html
- github.com/openbsd/src/commit/6c3220444ed06b5796dedfd53a0f4becd903c0d1 (Patch, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- security.gentoo.org/glsa/202105-12 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-35680?
- CVE-2020-35680 is a high-severity vulnerability in Opensmtpd, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2020-12-24.
- How severe is CVE-2020-35680?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2020-35680 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.