CVE-2012-4561 Denial of service in n/a
Remote attackers can cause a denial of service via crash in libssh due to invalid pointer free on error paths.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2012-4561?
CVE-2012-4561 is a medium-severity denial of service vulnerability in n/a, published on 30 Nov 2012. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The (1) publickey_make_dss, (2) publickey_make_rsa, (3) signature_from_string, (4) ssh_do_sign, and (5) ssh_sign_session_id functions in keys.c in libssh before 0.5.3 free "an invalid pointer on an error path," which might allow remote attackers to cause a denial of service (crash) via unspecified vectors.
Which versions are affected by CVE-2012-4561?
It affects 1 product.
Products include Libssh Libssh.
How do I fix CVE-2012-4561?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2012-4561 being exploited?
There is no known exploitation of CVE-2012-4561 in the wild and no public exploit code.
Other vulnerabilities in n/a
- CVE-2026-59851 Libssh: libssh: authentication bypass via missing gssapi principal check
- CVE-2025-5987 Libssh: invalid return code for chacha20 poly1305 with openssl backend
- CVE-2025-14821 Libssh: libssh: insecure default configuration leads to local man-in-the-middle attacks on windows
- CVE-2012-4560 Memory corruption in n/a
- CVE-2012-4562 Integer overflow in n/a
Sources
Also known as DEBIAN-CVE-2012-4561, GHSA-m2v7-9rhw-324g.