The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applicationsUpgrade Debian:10
maradns
to version 2.0.13-1.2+deb10u1 or higher.
Note: Versions mentioned in the description apply only to the upstream maradns
package and not the maradns
package as distributed by Debian
.
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for Debian:10
relevant fixed versions and status.
MaraDNS is open-source software that implements the Domain Name System (DNS). In version 3.5.0024 and prior, a remotely exploitable integer underflow vulnerability in the DNS packet decompression function allows an attacker to cause a Denial of Service by triggering an abnormal program termination.
The vulnerability exists in the decomp_get_rddata
function within the Decompress.c
file. When handling a DNS packet with an Answer RR of qtype 16 (TXT record) and any qclass, if the rdlength
is smaller than rdata
, the result of the line Decompress.c:886
is a negative number len = rdlength - total;
. This value is then passed to the decomp_append_bytes
function without proper validation, causing the program to attempt to allocate a massive chunk of memory that is impossible to allocate. Consequently, the program exits with an error code of 64, causing a Denial of Service.
One proposed fix for this vulnerability is to patch Decompress.c:887
by breaking if(len <= 0)
, which has been incorporated in version 3.5.0036 via commit bab062bde40b2ae8a91eecd522e84d8b993bab58.