Octorpki
CVE-2021-3761
HIGH
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Lifecycle Timeline
1DescriptionNVD
Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP "MaxLength" value, causing RTR sessions to terminate. An attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as "RPKI invalid". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues.
AnalysisAI
Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP "MaxLength" value, causing RTR sessions to terminate. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Out-of-bounds Write vulnerability could allow attackers to write data beyond allocated buffer boundaries leading to code execution or crashes.
Technical ContextAI
This vulnerability is classified as Out-of-bounds Write (CWE-787), which allows attackers to write data beyond allocated buffer boundaries leading to code execution or crashes. Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP "MaxLength" value, causing RTR sessions to terminate. An attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as "RPKI invalid". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues. Affected products include: Cloudflare Octorpki, Debian Debian Linux. Version information: prior to 1.3.0.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Validate write boundaries, use memory-safe languages, enable compiler protections (ASLR, stack canaries).
OctoRPKI does not escape a URI with a filename containing "..", this allows a repository to create a file, (ex. Rated cr
When copying files with rsync, octorpki uses the "-a" flag 0, which forces rsync to copy binaries with the suid bit set
Attackers can create long chains of CAs that would lead to OctoRPKI exceeding its max iterations parameter. Rated high s
OctoRPKI does not limit the length of a connection, allowing for a slowloris DOS attack to take place which makes OctoRP
OctoRPKI does not limit the depth of a certificate chain, allowing for a CA to create children in an ad-hoc fashion, the
OctoRPKI tries to load the entire contents of a repository in memory, and in the case of a GZIP bomb, unzip it in memory
If the ROA that a repository returns contains too many bits for the IP address then OctoRPKI will crash. Rated medium se
OctoRPKI crashes when encountering a repository that returns an invalid ROA (just an encoded NUL (\0) character). Rated
Same weakness CWE-787 – Out-of-bounds Write
View allSame technique Buffer Overflow
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External POC / Exploit Code
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