CVE-2020-23856
What it is
Use-after-Free vulnerability in cflow 1.6 in the void call(char *name, int line) function at src/parser.c, which could cause a denial of service via the pointer variable caller->callee.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.4% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.4% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.4% · EPSS, next 30 days
- Weakness
- CWE-416 · Use after free
- Record status
- Modified
Affected
- Gnu Cflow 1.6
- Fedoraproject Fedora 33
- Fedoraproject Fedora 34
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2020-23856.md and follow it. Check whether this project is affected by CVE-2020-23856. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://lists.gnu.org/archive/html/bug-cflow/2020-07/msg00000.html
- https://lists.gnu.org/archive/html/bug-cflow/2020-07/msg00000.html
References
- https://github.com/yangjiageng/PoC/blob/master/PoC_cflow_uaf_parser_line1284
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BLSXGFK2NYPCJMPHSHE3W56ZU3ZO6RD7/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FZTTKZX274BVFZX7TMPEZG6UWL6UPMQF/
- https://lists.gnu.org/archive/html/bug-cflow/2020-07/msg00000.html
- https://github.com/yangjiageng/PoC/blob/master/PoC_cflow_uaf_parser_line1284
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BLSXGFK2NYPCJMPHSHE3W56ZU3ZO6RD7/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FZTTKZX274BVFZX7TMPEZG6UWL6UPMQF/
- https://lists.gnu.org/archive/html/bug-cflow/2020-07/msg00000.html